What is the validity of French postage stamps?

[nomoss]

I received a letter yesterday containing a small Ebay purchase and was surprised to see two commemorative stamps on it to the value of 7.00 (no currency unit mentioned).

After a search I found they were issued in 1981 and 1990, worth a couple of Euros each as mint stamps in a catalogue.

They have been postmarked, so presumably are still legal. The current face value would be about 1€07. Click on small image to enlarge.

[url=https://postimg.cc/4K15Xmqs][img]https://i.postimg.cc/4K15Xmqs/Old-French-stamps.jpg[/img][/url]

EDIT: Found the answer myself HERE