To think that I hadn't seen this kind of double pulleys (or, not consciously, anyway) until a couple of months ago... now I see them everywhere.
Spotted at a flea market not far from here:
As (again) they were without companions, I left them for someone else to play with.
(And Jean, if you read this, the strange shaft-ties: I have given up on that, until I can get to the museum myself. They keep giving me the wrong references - )