Green's Cuba TB #'s 70-76, 1939//1952, were issued by the Jewish Anti Tuberculosis Commitee of Cuba (Colonia Hebrea Protectora de los Tuberculosos y Enfermos Mentales), in Havana, and have been greatly undervalued. I know of no dealer who has them for sale. Examining a single seal of this society, a Cuban philatelic expert who had never seen it, asked me how do you know they are Cuban? My only answer was, the larger certificate toward the bottom says, Cuba, and they have been listed in Green's Catalog, under Cuba for a long time.