That's a Simplex 440. It's one of the last, I think. Ask Chris at Velo Orange. He's selling them and he knows French parts.

Strap-on retrofrictions are on eBay all the time. I've got a couple of sets, But none to spare. The later, "open" type would be the one to go with that derailer. It's harder to find those in strap-on. You'll also find them badged Mavic.