I have found this manual for the Bellsouth 1010www.michaelknows.com/electronics/walkie-talkie-manual/
There is no picture to confirm it describes the correct model, but hopefully it will help.
As to a charger there is one on eBay for an unspecified piece of Bellsouth equipment.
Description: AC ADAPTER CHARGER. BELLSOUTH. Model
HB-35US-01. Input 120 VAC, 60 Hz, 5 W. Output 9 VDC, 300 mA. Output
connector measures 0.216", center hole measures 0.095". Center hole is
It looks to be available here www.sportslinkup.com/shop/0-300ma-ac-10-NEW.html
9volts DC at 300ma looks to be a suitable voltage and current to charge 4 AAA cells.
If it looks to fit you could purchase one for proof of concept. Try it out one one that is lacking in some way, and see if it charges 4 rechargeable AAA batteries. If it does not look like it plugs in, and the handset needs a cradle to charge, forget it, as I don't even know if you have a budget, and consider plan B.
If they are only to be used for training purposes you could consider running off batteries, changing them when flat. You could go through a huge number of alkalines, so rechargable might be advisable.
I don't know what you can get locally, but I get rechargeable batteries and chargers from China offeBay at ridiculously low cost, pity about the 2 to 3 week postage delay.
It's a rough and grotty solution, but may do for proof of concept.
And who knows? I'm in Australia and like the free postage options, you may be able to do better.