How so I fix a stuck piano key

Between 1925 and 1930. A more precise dating would require possibly examination of markings on the piano or a piano technician or a historian who specializes in vintage pianos. Piano Serial Numbers Search - Find the Age & History of Your Piano (total-piano-care.com)

Gulbransen Player Piano - Antique Piano Shop

1927 Gulbransen 55" Upright Piano (intunepianoservices.com)

Gulbransen Upright Pianos - Piano restoration & sales nationwide: Steinway, Yamaha & Knabe (countrypiano.com)

1920: Serial numbers around 140,000
1925: Serial numbers around 218,000
1930: Serial numbers around 301,000

It sounds like you are referring to the fallboard or key cover of your Grimmel Bros upright piano. To close the fallboard, gently push it up towards the piano's music stand until it clicks into place. The curved part you mentioned is probably the key cover, which can be lowered to protect the keys from dust and debris when the piano is not in use. To lower the key cover, grasp it at the center and gently pull it towards you until it lays flat over the keys. If your cats are causing problems by jumping on the piano keys, you may want to consider covering the piano with a fitted cover or keeping the room door closed to prevent them from accessing the instrument.

This was an easy search!

-Details of Ronisch Pianos-
Make Ronisch Made by Pfeiffer / Bluthner Rating (see Key) Estimated Number In UK Year and serial number 1855 -420 1875 -6100 1895 - 23000 1915 - 63200 1935 - 76250 1955 -78300 1966 - 100000 1985 - 185000 2000 - 209960 1 more row

Ronisch Pianos Information ' Roberts Pianos - Oxford

https://www.robertspianos.com > cdetails > Make=Ronisch...
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Ronisch piano serial number reference information. Find out ...

http://www.besbrodepianos.co.uk > pianoserialnumber
Find out the age of your Ronisch piano here. Simply type in the serial number into the box below then click "Calculate". Type in your piano's serial number:.

First determine what the material of your digital piano keys are. Many digital pianos now days have plastic keys but if you have those ebony black and ivory white keys, you need to clean them with extensive care.

1 - Use a damp cloth for cleaning your keys and make them dry.
2 - Use a small amount of liquid soap with a damp cloth.
3 - Clean dirty keys with this cloth. Your grip must be firm but rubbing must be light.
4 - Gently rub keys until they are completely clean.
NB: These steps can be followed for plastic keys but for ivory keys, you would need to get ivory scrapper

cant help with the serial number

if tuned casing and keys and strikers are in good condition
if buying from a commercial piano seller price 5 year guarantee
approx
Catalogue
7000 pounds UK
$6000 AU


The Ronisch piano has long been a favourite among piano teachers due to its fine, clear tone and highly consistent manufactured quality. Anyone looking to get a Ronisch is advised to look for instruments made before the second World War, as the original factory in Dresden, Germany was destroyed by allied planes in the latter stages of the war.
All of the manufacturing equipment was lost.
The factory was re-established in Leipzig after the war, but has never manufactured pianos of the same tonal beauty as did the original.

Carl Ronisch, was one of the foremost pioneers of piano-building in his time. He was first to use a full cast-iron plate in the piano, employing five struts and completely covering the wrest-plank (pin block), which for the first time, allowed a high-tension scale.
This is considered the beginning of the use of full cast-metal plates and is today, standard in the industry.

Ronisch instruments have won gold medals in the world exhibitions in Sydney, Amsterdam, Melbourne, Chicago and Paris.

https://www.alphapianostudio.com/

"Great teacher (Sandy) with lots of patient. Friendly and nice and also passionate till I have little time to rest my poor little hand. Learned for about a year plus and now can play more fluently and confidently. Price is acceptable and duration is just nice."

You'll likely need to try removing the keys, so you can see if something is stuck underneath it. That would be my first move.
In order to do this, follow these steps:

The front panel and the keyboard fall are designed to be easily removed for tuning purposes anyway.

To check it out....The front panel likely has a little clip either side near the top on the inside. Just undo these clips and lift the panel out. The keyboard fall should then be easy to lift out too.

There may be a long wooden rail which you need to take out also. Once inside, the keys themselves can be carefully lifted off the central spikes on which they sit.

Remember how you did this so you can get them back in again.

Since your piano is so old and worn, Often times, the wooden rail in front of the keys (just above your knees when you are playing) bows inwards a little due to age and temperature/humidity fluctuations. This then causes the little white front bit of the keys to jam against the wood and you have to physically lift the keys back up to return them.
If this is the problem you will need to take out the keys and shave some wood off the inside of this rail to allow the keys to move up and down freely again.
Or sometimes you may find you have a small object caught under a key or two. Much simpler to remove and free up your keys, if this is your problem..
Hopefully, this is all you will find wrong with your piano.
If all else fails...
I wouldn't attempt to tune your piano by yourself. I would seek out an experienced piano tuner for that.
But it is worth attempting to repair it first before you go that far.
Good luck !!

Milton Piano
From http://antiquepianoshop.com/online-museum/milton/ :
The Milton Piano Company was established in New York in 1892. In the early 20th Century they offered a full line of uprights, player pianos, and grand pianos, and they enjoyed a reputation of building very well made instruments. In the mid 1920s, Milton built a coveted new state-of-the-art factory on West 51st Street, New York City. There is some evidence that Brambach and Milton were somehow affiliated with one another, and their factories were located within blocks of each other. The Milton Piano Company built pianos until the late 1950s era.
From http://bluebookofpianos.com/agesm.htm#MILTON :
This name is a familiar one to the magical world generally. Milton pianos have been manufactured for many years and always with the care that produces most satisfactory results. The modern factories in which the Milton piano is produced are new, large structures located at 626-630 West 51st St., New York City. Milton pianos and player-pianos are thoroughly well-made, beautiful instruments, designed for a class of discriminating music lovers. They possess a tone at once powerful and sweet. They are pianos in which purchasers are assured good values and they are pianos that give exceptional satisfaction. Milton reproducing pianos are equally representative and popular.
All of which is great, but:
Be aware when dealing with antique pianos:
Many of the old (say, 1850 to 1940) pianos were made by companies that are no longer in business (failed, or bought out by a competitor), or companies that built the instrument under another name.
Pianos back then were not really mass-produced, they were hand crafted- and each manufacturer made their piano very differently, so:
Short Version: there will be parts that will work on only that *one* model of piano, so getting parts will be difficult if not impossible.
Long Version: Musical instrument craftsmen (craftspersons?) love to innovate, for a variety of reasons: they may find a new way, for instance, to connect the key to the hammer that strikes the corresponding note. It might be a better way to do it, or, more often, it was to come up with a cheaper way to do it.
The point I'm making is that your Struz Brothers piano will have parts that are totally different from, say, a piano made by either Krakauer Brothers, Doll, Jacob & Sons, or Mathushek & Son Piano Company (companies that started around the same time as Sturz Brothers). The parts may vary from one year to the next, or even one model to another.
So, if your Sturz Brothers piano needs a key replaced, or the harp has bent under pressure, the soundboard is cracked, or any number of things that can plague an old instrument, you'll need to either
A) find someone that is willing to sell parts from a similar model (if they're parting it out, it has more problems than yours does), OR
B) you'll need to have the part manufactured from scratch by craftsmen that specialize is rejuvenating old pianos. This will be expensive far, far beyond what the piano is worth- and these craftsmen live very well, BTW...
Last Caveat: Upright models sell for much less (and the term "Upright Grand" was just an advertising phrase, there is no such animal.) Uprights (spinets particularly) sound very... tinny, is the best description I can think of. Tinny like the toy piano your granma gave you when you were five- remember, the black keys were painted on? Tinny like that.
So, unless the piano is a Steinway & Sons, a B?sendorfer, or a Fazioli, don't count on huge offers for your instrument. And if it came to you from your great-aunt Tilly and you can't bear to part with it, that's great, I understand sentimental value. Just know that this will cost a great deal to bring to playing condition.
I'm often told "But the keys all work, the pedals are still tight, and the tuner told me that it's not a bad piano!" All this is true. But please remember that professional buyers know all of these potential pitfalls won't offer much, and the guy on Craigslist that needs to replace the piano for Great-Aunt Tilly can't afford much.
Good luck!