I picked up 2 recently with the cable stop. The upper pivot on the later one seems loose and the arm hits the limit screws, not sure how much it's worth but I'm gonna sell them both on ebay. I know this is a really long shot since I am one of the few super intense campagnolo nit pick detail guys on the forum but here goes anyway and without pics too boot...

the one I judge to be early (i believe it first appeared in catalogue 14 (1958)) has thinner lettering on the front of the clamp and the shape of the triangular area has more mass and a sort of elbow on the bottom (holt crap I need a camera)... It seems to be working well although I will have to replace some of the incorrect nuts and bolts with proper ones. Overall it's in pretty good shape. The later on is similar to my first generation Nuovo Record FD in that it is a triangle.

SO this brings me to my question and point of discussion, which I fear will bring little discussion! Does anyone know what year this revision might have taken place? Remember these are BOTH early record with chromed brass arms and cable stops... Now that I write this I think I just might have to keep them for display.