Looking at photos of the above-mentioned tanks, it seems that at one stage they went to a dipole aerial instead of the monopole aerial. The also had a dirty great big hose reel on top.
I hadn't seen this mod before. The cable drum might also be for laying communication wire. Here is another version with a jib on the turret. I am not sure if it is inter war or WW2 or even if it is French or captured German mod.
Presumably the jury-rigged crane or jib was a temporary thing to lift off the engine covers? It certainly doesn't look big enough to lift out an engine.
There are places on the main turret to fit the crane's legs, so this presumably was something that needed doing at regular intervals
The cable drum/hosepipe reel was obviously a temporary thing as a rope balustrade was put up during its operation - see the attached pic
