Pete, this looks to me like an attempt to salvage a sand mold that had been damaged. There is no real reason for the manufacturer to have added these rough extensions because this tank weould have had the wet ammo stowage common to the 76mm armed Shermans. Note that many late production small hatch dry stowage M4A1s had the applique armor panels cast as part of the hulls, as Steve Faxon shows in a couple of his resin aftermarket Sherman hulls. I saw a couple of these hulls myself when I was at APG before leaving the Northeast for Texas in 1979. This is interesting texture, but I doubt it has any function beyond fixing a sand mold that had collapsed. I'm cheerfully prepared to have Steve Zaloga or another Sherman guru weigh in and tell me I'm all wet....
