I have a circa '77-79 Colnago Mexico. The rear brake bridge is the earlier style before they changed to the block style. Mounting the rear brakes I noticed it appears there's a piece missing. It resembles a spacer that is flat on one side and curved on the other to match the contour of the brake bridge.
Without the piece the flat washer contacts the curved surface of the brake bridge and does not look correct.
I saw the part on a 1977 gold plated Olmo on the speedbicycles site. I would post the pic but do not have permission.
Anybody know what this piece is called? Is this something Campagnolo produced?