Mmm pongo, Ostketten or just wider tracks, used to better manouvre in muddy ground (better weight displacing, they just watched the T34 manouvrability and said hey, we want that too

...) Schurzen are thin metal plates covering the tracks (from the side) and the tower designed to let rounds predetonate on them or change their flightpath (so they don't hit the main armor, or just bounce off).
If it's a Normandy PZIVH, you are right about the ostketten, but I believe Schurzen were standard issue on all PZIVH.
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BEE
'Nemo Impune Lacessit'
JG2 "Richthofen"