Hi!
I can't tell you exactly the length of bottom bracket, but with 85% certainty, if I remember well, it is 118mm Stronglight Competition like this
http://velobase.com/ViewComponent.aspx? ... p;AbsPos=8.
Headset is Competition V4 model:
http://velobase.com/ViewComponent.aspx? ... ;AbsPos=14
Both bottom bracket and headset came with my bike and they were excellent condition, as per quality it is top notch. The best source for parts is french ebay, where you can buy them for half the price comparing to UK and there are tons of parts from that era to choose from.
You can't go wrong with Stronglight 93 crankset, just remember that it has a proprietary remover, 23.35mm that could be expensive for what it is.
https://www.spacycles.co.uk/m2b0s72p268 ... -Extractor
Threading, of course, is French all the way
As per other parts, there should be: AVA stem, Simplex Criterium gearset (I have upgraded with later version Super LJ, so not so period correct..), Mafac Racer brakes and MAFAC Course 121 levers, Pelissier or Normandy hubs, Cyclo freewhell, Lyotard 45CA, Simplex seatpost (old chromed steel version), Selle Ideale 2001 or Brooks Pro saddle.
Since I went for full self employment I don't have so much time for fiddling with bikes any more (still, I ride them all the time) apart from that now I'm in the process of moving flats and I need to reduce my collection... so anyway, if anybody interested in any of my bikes, give me a shout... parts as well, have tons of them.