Another 'help what is it' appeal

I think you could be right about the fluid-coupling drive for the supercharger.

From the angle of the bevel gear it looks like it is designed to be driven at high speed by a much larger bevel gear.

German props used a non-reversible pinion gear for pitch change. It doesn’t look prop, more engine.

The heavy bevel gear must be the biggest clue. There appears to be the remains of engine casing (possibly mag-alloy) to which it would have been mounted. More likely an inclined drive to a camshaft or accessory.

Having had another look, it may be a bit too big for that – possibly a fluid coupling to a supercharger looking at the heavy body. The ragged bits at the far end could be the remains of the impeller.

Merlin Pete has some experience of German motors so, hopefully, he might be along to positively i/d it soon.

Anon.

That would be my guess too, part of the prop hub and the blade root. I know absolutely nothing about German props though….

I would say its a prop base socket ( not sure of correct term) wooden blade which fits into the hub and the drive on the bottom for pitch control/ feathering. I am sure some of the clever ones will be along shortly