That's a nice looking 3D drawing. I have two suggestions, though. The driver and co-driver's hatch should not have the guards over the periscope, those weren't put on Shermans until later in 1943. Also, the armor over and behind the hull mg mount should be thicker and wider than what is shown.
I'm glad that you guys are going forward with the early dv M4A1 hull option. Not that I won't be buying the later M4A1 small hatch hull, I definitely will, but it will be great to have options to cover the entire course of the conflict