I cannot find much on these, and I'd love to know where the slot into history. they were obviously made by Gillette in France and the box is unopened, it feels like 10 blades in there, my feeling is that they must be pretty rare and one person is going to be very happy to come across this pack for his set. Give me some dope on them if you got better Google skills than I!
Note* For obvious reasons vintage razor blades are a lot harder (and more expensive) to find than vintage razors, and such items will come and go on our website, grab more than one pack if you could, one to try out and one for your collection, soon enough they may not be available at all!