Gino, like the product description states, these are WITH mud shields, aka "early style" wheels.
M26 had them from the begining. They seem to have been started to beeing replaced in the early '50s, but you'll may find them on M48s as late as in the early '60s. The wheel itself were the same from M26 to M60 (steel wheels that is), but the early ones hade a sheet metal cone welded inside. (Same thing with M24/M41: early wheels had a mud shield, later did not.)