Unissued, Cérès 1st issue Y&T n°8b bleu dit "Astruc" 20c mint with almost ** original gum (tiny adhesion). This stamp was intended to replace the black 20 centimes and was not issued due to a change in tariff. The names correspond to the discoverers of this stamp. Very fresh and perfectly proportioned margins. A rarity in French philately. Signed Behr and Brun. Scheller certificate (2019).