Hello
There is two kinds of restoration for old military vehicles. Some are done with a great accuracy but other like the SHERMAN you have seen are done with the main goal that the tanks are rolling.
So the most SHERMAN you have seen have MAN diesel engine instead the fuel CONTINENTAL 9 cylinders for the M4 and M4A4 and also a diesel MAN engine instead the two GM diesel for the M4A2. Inside some of them, the sticks used for directional have been replaced by a joystick and all of them own an internal network TV with a little camera at the rear top of the turret so when you drive the tank in reverse you can see where you go
The source of these tank is an association BALMORAL GREEN managed by a man who had great relation with french military. So most of the SHERMAN are issuing from scrap belonging to french army or static monument.
I give the address
www.balmoralgreen.com
Regards Serge