From: "Jeff Slotkin" <email@example.com>
> >Greg Parker supplied this web link:
> ...so, click on it, look at the "miscellaneous Mafac" pic that appears;
> there is a bolt/washer/spacer/nut assemblage at lower right in the pic.
> What is it? (I have a bunch of them).
It looks like the rear caliper mounting bolt for a bridge made of round tubing.