Hello Bob, I have always thought that most cycling innovations and improvements start with the racing scene, if you look at any pictures of the famous tours or classics from the various periods you can normally find pictorial evidence. With this fact in mind I have had a quick perusal of the 70's photos and found that the earliest frames fitted with full runs are Gios and Bianchi in 1975. Looked later and by 1977 practically every Italian maker has them on but Merckx team is still using Campagnolo cable clips and so are TI Raleigh. On this evidence I think we are both about spot on regarding the dating. Still got some earlier 70's pictures to wade through will let you know the results of my findings
Thats all for now. Keep those wheels spinning, in your memories if not still on the road. Be lucky Mick Butler Huntingdon UK.