A lot of french frames only have a rear mech shifter braze-on. There are left-side boss-on-band bits that have a cutout to allow the brazed-on boss to poke through. Check ebay item 131115024231 for an example.
You should also check if your frame tubes are metric sized - if they are, keeping the front mech from slipping means either getting a smaller clamp or making a shim.
A lot of french frames only have a rear mech shifter braze-on. There are left-side boss-on-band bits that have a cutout to allow the brazed-on boss to poke through. Check ebay item 131115024231 for an example.
You should also check if your frame tubes are metric sized - if they are, keeping the front mech from slipping means either getting a smaller clamp or making a shim.