Well, Chuck, you write that most pro riders used handlebar tape to fix brake cables to tup tubes in the very old days.
Thing is, there were much nicer and much more functional things around even in the thirties, like rubber straps that could be undone in a sec, or the famous Rosa metal clips that were even available specially made for small dia dual cyclo gear cables on one side and a fatter brake cable on the other, all in one clip.
Can´t think why they should not have used them but stuck to sticky tape. Matter of fact, you do see those things on old photos, too.
Regards, Toni Theilmeier, Belm, Germany.