Not sayin' that french bikes can't be a PITA,but i converted a Mirage and had only minor problems.The BB was swiss and even though standard cups are not supposed to work it worked out with some cheapo cups.They went in a bit on the loose side but tightened up fine and i rode it for a winter as my beater before giving it to a friend who rides it pretty much daily without problems.The fork/headset inside diameter was 22.0 instead of 22.2.Again,it's not supposed to work but a SR quill stem of a nishiki frame went in fine(sanding down a old stem works fine too).Being a beater i kept the seatpost.
A old hi ten motobecane is certainly not a frame to dump a lot of $ into,but if someone already has one it's only a matter of checking a couple things(BB threading,diameters)to see if the bike at hand can be converted without too much fuss.