Hello,
Somebody can it inform me about the presence of these spots on these stamps.
Thank you.

bonjour cousin obelix,
all i can say for now is the possibility of them being a type of precancellation much like is done to u.s. stamps. they could be privately done to twart theft of stock or done to trigger the cancellation machines to reject the letter, but a machine cancel on the one stamp might make this theory null. hope someone has a better story. i gave it my best.

amities et a bientot,
cajunsr.