The thing that looks like a shovel is actually a deflector. The external mufflers underneath were standard on the Pz IIIs up to the Ausf L and the Stug III's. Early models PZ IIIs(and I'm guessing Stug IIIs)did not have the deflector over the mufflers. Ithink the deflector first appeared on the Pz III H. The picture I sent of the PZ IIIH Tauchpanzer is a special case. Its a modified PZ IIIH for deep water wading. The standard rear muffler was removed and replaced with a special unit that would prevent the backflow of water into the muffler/engine. In the picture I sent you of the PZ IIIHtauchpanzer the muffler is not installed. The deep wading muffler type reappeared as standard on the PZ III M and N for all units.