Oops, my bad about the photos -- I need to read a bit more carefully sometimes.
As to the existence of a large-hatch M32B1 -- I am still very dubious and would want to see photo evidence. Many dedicated Sherman researchers have sought this elusive (and probably mythical) beast for a long time and have not found a single frame of film showing it.
I have been studying and modeling variants of the Shemran for about 20 years now and don't claim to know all the answers. Indeed, some Sheman "myths" have recently been shattered -- including the existence of a non-Duplex Drive 75mm M4A1with late hull, and the use of early M4A3 75mm gun tanks in combat. It does seem to be "never-say-never" with Shermans...
However, it would not be quite as easy to "jury rig" an M32B1 as your post implies. The actual conversion of an M4A1 gun tank to an M32B1 would be a monumental task -- not just a simple swap of a few parts. Maintenance crews might cannibalize parts from one vehicle to fix another, but creating a tank recovery vehicle from a gun tank would involve major modifications of the hull, way beyond simply swapping out a few parts.
It would also be totally illogical. The Allies needed as many gun tanks as they could get their hands on and keep running. Why would they sacrifice a gun tank to create a recovery vehicle?
Build whatever makes you happy, Jacques, but I'll stick with what I
know existed, not what I think
might have been out there. But then again, I am an AMS-afflicted rivet-counter ...