bradl When I purchased my UO 8, I included a set of clinchers that had Rigida 1320's. With the option, I would use the clinchers for most rides, which included commuting to work, and use the sew-ups for fun rides. BITD there was a significant difference between the two. I was sold on the sew-ups with the improved performance.
My wife's 1974 Raleigh Gran Prix has the same set of derailleurs. The band has not broken but I need to find a replacement.
3ttt made a stem for French steerers. My 1972 Motobecane Le Champ came with one. I have seen them on CL upon occasion.
LC_Stem, on Flickr