Dear Mr.Stone, You said the following "Fashion certainly played a major part - if function was the main consideration everybody would have been using Simplex or Suntour rear derailleurs, Suntour front mechs, Stronglight chainsets, bottom brackets and headsets, Shimano Dura-Ace brakes - with perhaps Campag pedals, and hubs in the 70s". Well all I can say is most British racing cyclist's were still predominately into time trialling in the 1970's and if the riders who rode Norlond Combine events are anything to go by, they would have no need for a front mech and functionality was a must not fashion! Who the hell wants equipment failures when you are on a PB only to record a DNA because of technical problems. The majority rode Stronglight or T.A. chainsets, mixture of Campag and Stronglight headsets, brakes were Weinmann, Campag or Universal and hubs as you correctly say were Campag. A hell of a lot of riders were using Suntour rear mechs and Huret Jubilee (late 70's) for their five or six straight through blocks with a few on Zeus, majority rode Campag rear mechs. The real top testers had only three sprockets on their blocks. I can only ever remember seeing schoolboys, juniors or novices riding Simplex rear mechs in the 70's. When it came to road racing everything Campag was the norm. Can honestly say that I can't remember ever seeing any of them with Dura Ace brakes until the 80's. So there were a lot of people testing on the kit you mentioned not everyone but not that uncommon.
Frank Cohen Hoxton UK