The tank in the famous photo is an M4A3E8 - the last major factory-built gun tank. Andy chose to do an M4A1 76mm Wet Stowage, slightly different. Yes, you can put the muzzle brake on the gun. Both the tank in the photo and the Strictly Limited model have 76mm guns. Late M4A1s DID come with muzzle brakes on their 76mm guns and would have come into service about the time that the sandbagging became popular.
FYI, the function of the muzzle brake (not "break" as often misspelled) is to reduce the recoil force of the gun. The expanding gases push forward against the baffles. Another function is to push the muzzle gases to the side, reducing the amount of dust kicked up. That allows the tank commander to better sense the effect of the shot and lets the gunner adjust for another round.
Another trivia - although Patton is criticized for telling the troops not to use sandbags on their tanks, he did have Third Army shop crews canabalize wrecked Shermans and add the steel armor to a number of M4A3 and M4A3E8 tanks.
More trivia - that poor crew in the M4A3E8 were likely from the 14th Armored Division or another Seventh Army outfit that may have come under Third Army command. The Seventh Army had an active program of adding the full frames full of sandbags all around the tank.
Gary