French Obsolete Ammo site

Many old calibers and boxes as well as modern manufacture of obsolete cartridges.some nice boxes
https://rolly-armes.com/cartouches.htm

New obsolete caliber ammo (much the same as Rolley armes):
https://www.azurarmes.fr/47-cartouches-neuves-poudre-noire-pour-armes-de-collection.

The ammo on the new obsolete link looks to be mostly that which Megret made / reproduced.

Yes both have a lot of Megret boxes. The first though has some older boxes as well.