I have a Raleigh Professional from about 1975, and when I shipped it here, I detached the Campy derailleur so the bike could fit in the box. Well, apparently the bolt that connects the derailleur fell out of the box, or something, so I need a new one.

Does anyone have any idea where I could find such a bolt? The local bike shop didn't even recognize the thing... (took a matching one from another bike to show them)