Jon,
You are very fortunate that your bike is painted in one of the 3 colors where an exact color-match is not very difficult (white, black, or silver). I would NOT recommend a full stripping and refinishing of this bike, as you could much more easily sand off the rusty areas and overspray them with additional primer and/or white paint. A new 531 decal and some touch-up on the seat-tube bands and/or Peugeot logos should be all you need. That will keep the bike more original, and more accurate. Your seat-tube decals are nearly perfect ...
I've done oversprays on 2 bikes ~ a Carlton Pro and Gran Sport. Here is a web page describing the Carlton Pro work :
http://www.ece.ubc.ca/
The trick is to not use too much paint, and make sure to sand the bike after every coat (even primer) to get an even finish. As for your head-badge, indeed it's kind of munged and scraped up and I think those 1960's badges are not too common but it's no different than the badge on a UO-8 / low-end bike, so a visit to a used bike shop or do some searches on craigslist or on ebay or even at the dump to turn up a "donor frame".
As for the chrome on the rear triangle - I did not see any bad chrome on the bike and french chrome was not really mirror-quality, it was more "rider quality", which means there was probably no intermediate polishing step between layers of copper / nickel / chrome. have you considered a much milder process, just brush-chroming any rusty spots on the rear triangle ?? These kits are useful to have :
http://www.caswellplating.com/
This can also be used e.g. on the small parts for your shifters. Note that if you were to go whole-hog and refinish the frame in shiny new chrome and paint, the cranks and derailleurs would then look out-of-place on such a frameset. So I think a milder and more gentle restoration is warranted for this frameset.
- Don Gillies
San Diego, CA, USA