I've never noticed what the big deal about putting a 22.2 stem in a french bike is. I always run a brake hone in the steer tube 1st, for just a second or two. Not to remove metal, but, looking for a burr. I put a slight bevel at the opening, maybe a mm in depth. I adjust the head set and then use my 22-23 mm adjustable reamer to get both holes the same diameter. Buff the lock nut with 1000 paper and grease the stem and the weight will make it slide in. The Top lock nut is the culprit. I only use Nitto Deluxe stems. Try something some time, take a digital caliper, set it on mm, and open it up all the way to .2mm. Wow you can't hardly see it. Older European bikes are not the most precise critters ever made.
Dickey Greer
West Monroe,La USA