I don't know the answer to the TDF question, but these bikes were sometimes built with Osgear rear dropouts.....this one might have had them too, but if it did, they've been removed....old school puppy killing!
I was just knocking back the hand painted lumps, when I went through to grey primer.....then after a bit more, through to the original paint. The downtube started to show some orange, and then I uncovered the decal. This will take some very, very carefull use of wet and dry paper to uncover them fully......and according to any other web resources I can find, I haven't seen decals on the down tube the same.......anyone else seen them?
I'm going to try to remove the old crud and primer, then try to preserve whatever is left......we'll see.