ID for 4 speed automatic

This has a 3 wire connector and it's lock up and OD. I don't know enough about these to know which numbers cast in the case would tell me something, Where the serial number would be, how to figure the year of manufacture, or which pictures to post that would help the ID...
You don't want cast numbers, there should be a string stamped into the pan rail somewhere.

This might help......found this Russian site which has ATSG manuals free

Коробки передач | Интернет-магазин запчастей для автоматических коробок переключения передач

RH series manual:

http://shop.ukrtrans.biz/wp-content/uploads/catalogs/42RH.pdf