As Michael commented on the headbadges found on all Bobet frames..there are some fine photos of the self-adhesive badge in the Bobet section of the Classicrendez-Vous site, if Kim wants to check them for "a fit" in his headtube.
These badges resemble very closely the Mercier self-dhesive design, a thought that makes me wonder if perhaps at some time Mercier's Service de Course workshop ever built top-class frames bearing other "maker's" transfers?
Norris Lockley..Settle Uk...going to a Jumble tomorrow!!