The Sherman in this pic is an M4 composite hull, the front hull is a big casting, welded to a welded rear hull. These saw action in the Pacific, and a number of them got turned into Composite hull IC Fireflys. These tanks had improved larger drivers and co drivers hatches, but still used dry ammo storage, the extra armor over the ammo racks was installed at the factory, and the cheek of this tanks turret was probably cast thicker, so the add on armor was not needed.
The big change in ammo storage came when the M4A1, M4A2 and M4A3 tanks were upgraded with improved turrets, with the M1A1 76mm gun. All these tanks had the improved large hatch hulls, wet storage and commanders all around vision cupolas. The real difference with wet storage was the location the ammo was stored was changed, instead of being in the sponsons, it was moved into the hull, in the floor under the turret. To make it easier to get to this ammo, the turret basket had half the floor removed. This location change, coupled with an 8 round armored ready rack made the ammo much less likely to be hit, and the location more than the wet racks made the difference, and the water jackets were dropped by the US right after the WWII.
There were dry rack, 75mm M4A1 tanks made with cast hulls that incorporated the armor in the casting over the hull ammo racks.
As for what the crews had for personal weapons, they all had a trusty 1911A1, and on the early Shermans, the tank had one Thompson, and they crew was instructed to take one of the .30 1919s with them if they bailed.
The second Gen Shermans, IE anything with large hull hatches, each crew station had an M3 Grease gun handy.
Check out this spec sheet for the Easy 8 Sherman.
Anyway, I hope that helps.