- bsmart
I think the hull looks like an early M7 Priest. The Right side doesn't have the setback gunmount that the Grant would have.
Possibly s 'defrocked priest' disguised with a fake turret?
Or, it's a false front superstructure to make it look more like a Sherman since the Grants had been replaced by them by the time some of the command vehicles were made. Note the round protrusion on the right side of the false glacis. It's probably supposed to represent a Sherman type antenna pot.