TRANSMISSION ID HELP - need transmission ID assistance

[CousinTone]

Hi all, I need your collective knowledge to identify what type of transmission I have here. It was given to me by a great guy who has 3 fully restored El Morocco’s down in San Diego. They were beautiful. Marv is his name and you can see his cars in the upcoming Mecum Auction in Kissimmee in a few weeks. He’s going to be a very rich man soon, if not already.

Back to my quandary. He gave me this transmission with the purchase of some of his extra engines. It appeared to be a rare overdrive unit with the solenoid looking thing-a-ma-bob on the side, so I kept it (hoping it was) and it’s time to see if it’s an option for my 64 C20 LongFleetside with 3 OTT 292. I have done my best to highlight the casting numbers but have been a bit lazy in the cleaning dept. I’ve googled so much I am stumped and know you are all smarter than google. It has 10 spline input and 29 out (if I counted correctly, I’m missing a finger, so I’m easily confused).

Let me know if any further info or pics are needed/wanted and I’ll get those done immediately.

Any help, input and/or guidance would be appreciated very much. Thanks in advance for all your help. Tony “V”

I’ll work on getting it cleaned up since I now have some unwanted Covid time off and update post when I get that done. Thanks again. TV