Please help me identify these

I would like to know the countries, and possible when they were issued (what decade or so is sufficient for me).

B is connected to France, I suppose, with the RF. Was Mermoz a colony?

C - Poland used Doplata, but maybe more countries did. I've seen Poczta Litwy Sprodkowej, used for an area in Lietuva, but the last word on the stamps doesn't seem to be that word.

2009-08-10. E-mail:
Text/pictures: Arne Granfoss and Björn Granfoss ©. Prod: AG Informice