Duston listed under „Comoro Islands“ only 50F and 100F, with the Duston description: 1975 (Post Independence). I would write: After independence from the motherland France. Duston continues: Medaillion with star, inscribed ETAT COMORIEN, 38 x 22mm, white unwmkd paper, value in black, perf. 13½.
My description is: Issue year unknown, you can also see a medaillion, but with a star and a half moon, that stands for (Moon Islands = lunar archipelago), these are probably a stamps new TIMBRE FISCAL edition from 50F to 3000F and the stamp with the inscription “FREE”. There will be more value levels. 40x 23mm, white unwmkd paper in snow white, value in black, 13¼ x 13½