I am rebuilding a Winchester Model 68 22 caliber and am looking for a manual or exploded view on line. It came in pieces but all seems to be in order.

Numrich for parts always.

Winchester Shotguns 37A - Numrich Gun Parts

https://www.gunpartscorp.com > shotguns-win > 37a-win
Find Winchester Model 37A parts and schematics today with Numrich Gun Parts. Providing parts since 1950.

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  Winchester Shotguns 37 - Numrich Gun Parts

  https://www.gunpartscorp.com > shotguns-win > 37-win
  Find Winchester Model 37 parts and schematics today with Numrich Gun Parts. Providing parts since 1950.

1993 WINCHESTER Model 37A Shotgun Schematic ... - eBay

https://www.ebay.com > ... > Other Collectible Ads
1993 WINCHESTER Model 50 and 59 Automatic Shotgun Exploded View Parts List ... 1992 MOSSBERG Model 500 & 590 Mariner 12 gauge Shotgun AD w/ original prices.
US$10.95 · ‎In stock

THE CORRECT AMMUNITION FOR YOUR FIREARM IS INSCRIBED ON THE LEFT SIDE OF THE BARREL IF YOU WOULD LIKE AN OWNER'S MANUAL, COPY AND PASTE THIS ADDRESS INTO YOUR BROWSER'S ADDRESS WINDOW ( http://www.winchesterguns.com/content/dam/winchester-repeating-arms/support/owners-manuals/12-wra-332-model-70-om.pdf ) AND PRESS ENTER FOR A FREE PDF DOWNLOAD FROM WINCHESTER

Savage had a long history or caliber changes with that rifle. Anything from for .303 Savage, .30-30 Winchester, .300 Savage, .25-35 Winchester, .250 Savage (also called the .250-3000 Savage, .22 Hi Power, .22-250 Remington, .243 Winchester, .308 Winchester, .358 Winchester, 7mm-08 Remington, .284 Winchester, .38-55 Winchester, .32-40 Ballard, .375 Winchester

The most common stamp showing c3 was for 22

Winchester - Model 1876

• Winchester 1876 .45-60 (W5880) Winchester 1876 .45-60 caliber rifle. Made in 1883. Unusual gun as it has a half round half octagon barrel which is something you rarely find on a 1876. Gun is excellent with approximately 97% of the original finish. Wood is...
• Winchester 1876 .45-75 (W2960) Winchester 1876 .45-75 caliber rifle in 35xxx serial number range with 95% blue overall and excellent wood. Has a tiny T.J.H. on receiver. This is a top condition '76 with factory letter.
• Winchester 1876 .45-75 (W3037) Winchester 1876 .45-75 caliber rifle with very good wood and metal. Rare 7 leaf sight called for in factory letter. Rare 7 leaf sights are found on some 73's but not mentioned in the factory letter.

http://www.gunpartscorp.com/Manufacturers/Winchester-33573/Rifles-42602/63-40325.htm

Look up the serial number in http://www.winchesterguns.com/support/files/images/wfa/2012-All/2012-Articles/Winchester-Manufacture-Dates-by-Year----2012-Scanned-Documents.pdf

You can find a small but useful exploded view of the gun here.

You can see the parts list by scrolling down on that page.

They sell a better exploded view (which they call a schematic) parts list which you can download for $1.50.

What Winchester calls the magazine plug is shown as drawing reference # 54.

There's an article on plugging a model 12 here.

Here is a video from an armorer's course about the model 12: