quoting myself From POST 1
As an aside this may also go some way to explain the purpose for these 3 mysterious hooks. If they were a replacement for the 3 individual links then presumably they were fulfilling a similar function
Throughout the Panzer IVs development spare tracks were used as a supplement to armour protection. Presumably the 3 links on the rear plate fulfilled this function to a certain extent. A rear view of the Saumur PzIV/70(A) shows a length of 9 links hanging from these hooks and the fit seems very neat. The folded square nature of the hook also seems to suggest this use.
If this was the intended use another possibility is that, as most of the images of late Ausf Js are of destroyed vehicles, any explosion could have dislodged the track length.
I am clutching at straws here I think but who knows?
Image 3: dislodged maybe? Plus a 4th hook ??
However this is only one image (and a maybe) and in every other rear image of Ausf Js with this feature the only thing hanging from it seems to be the towrope. I would just add that the hooks do look to be considerably over engineered if this was to be their use. Why, if the agenda driving change and development was simplification and economy, did they attach 3 hooks so the tow-rope could be stored more neatly?