Ha, thanks! The forward hub center has a tiny text I would never have noticed if I hadn't known to look: NORMANDY P 13 75

The serial number would suggest 1972 for the frame, but the front hub 1975. I don't think they kept em in storage for 3 years before putting on a front wheel. When googling for a PX-8 I can see someone else was selling one in 2003 (incidentally, I got mine the same year but it's not the same, this is an abandoned bike), so they at least were sold in this country.

From the decals it seems this is from 1970-76 but the down tube decal doesn't fit any category: there are inclined cut gold strips at both ends but the lines do not extend below the text. Like the french colors lines but gold. Or then the description is inaccurate and it is category III and 1974-76.

I took the wheels out and cleaned the chassis and a bit today. The front chainwheel is Nervar. Tomorrow the wheels (I'll examine the rear hub then, now it's under thick oil-mud), and if I get a chain breaking tool, I'll disconnect it for cleaning too.

EDIT:
This seems to nail it, I found a PX-8 that is on sale in Holland and it looks similar to my bike except for color and a tiny bit different decals. If you compare this
http://www.marktplaats.nl/index.php?...n.html%23photo
to the first picture in the thread you can see that they are identical, except for some decals, which probably means a bit different year.