Very interested to know how it's winding... Probably the screw head on the other side is compressed against the brass wheel and the two are permanently jammed together.
@Archer Unbelievable right? No idea, just purchased it, and it was conveniently hidden in the seller's photos. To my untrained eyes it looks like the last service was many years ago.
@Canuck I'm pretty sure it does wind manually, I heard it slipping once and I thought it was the rotor, now I know what it was.