Too bad Norris Lockley is not on the list. Good question and an observation.
I would think if one paid enough, they would get their initials on a cap. The pro bikes I have seen (pictures) by BC were not exactly well finished. They were tools. Custom bikes for an individual usually (emphasize usually) would have been finely finished. How about some more pics of what you have?
FWIW, Gilbert Bellone was a member or the Sonolor Lejeune team in 1970 and 1971.