Heya, Boyne Water!
Can’t find anything definative, but from study of different M3 and Ram tank photos, I’d have to say that they are pretty much the same EXCEPT the M3 machine gun turret has 2 protected vision ports at the 3 and 10 o’clock positions. The Ram aux machine gun turret appears to just be a simplified M3 turret minus the vision ports. They share same shape, mantlet, and hatch arrangement. Even the mantlet trunnion bosses appear the same.
Hope this helps…
Russ
Proud son of Rose and Wes