That's something you'd need to build from scratch rather than say just using a Sherman. Something which looks "like" a Sherman overall would do, but I'd be mixing in different kits (of different scales too, for instance an oversized turret). Hmn, aye bits off of a Sherman, Patton, something with angled tracks and well whatever toy kits look right would do. The thing's a bit mental looking, but I don't know if you're just wanting a basic looking tank to snazz up a bit with the decal, or to slap together a load of kits (hmn, though I suppose you could get away with just mixing a hull with a different body if that's enough for the weird look).