The bike is probably a Gitane. The steerer is a
Nervor not a Nervex. Gitane used butted Nervor steerer tubes on most of their bikes from the 1960's throughout most of the 1970's.
The forged Phillipe stems were some of the most beautiful ones made. They didn't become readily available until 1975 or 1976. Those stems came with Phillipe, Peugeot or Motobecane logos embedded in the sides.
The classic 3TTT Record Strada stems have a classic look and were more period correct for bikes during the bike boom - 1970-1974.
As a side note, French/Metric stems were 21.9mm not 22.0mm - you can't fit a 22.0mm stem into a 22.0mm steerer!
Many stems are slightly undersized. The bores on many steerers are slightly oversize.
Most of the inch size Nitto stems marked 22.2mm that I've measured are actually 22.1mm and they'll fit into many French steerers.
Just one more thing...
1. I recommend filing a slight chamfer inside the bore of the steerer to remove any burrs so the stem slides in easy.
2. Clean out all of the olde gunk inside the steerer.
3. Use a brush hone or sand paper to smooth out the bore.
4. Put a small glop of grease inside the steerer and some on the stem (do the same with seat tubes - there's no excuse for stuck stems and seatposts).
5. do not tighten the top lock nut on the headset until the stem is adjusted and tightened.
verktyg
Chas.