Cuba 1930 - Sc C3 (EDIFIL 254) - National Airlines Inauguration. The 1930 stamp issued to celebrate the inauguration of the National Airlines. This is an extremely rare, unused, original gum, hinge remnant, Plate Block of 4 showing the OTTAWA - No. A -1 marginal inscription. There is a hinge remnant between the two upper stamps. This very rare plate block is not even listed in the ECOFIL (Guerra Aguiar) Catalogue of the stamps of Cuba that has a 6-page section at the beginning of the Catalogue, listing all the known plate blocks of the Republican period. A very hard to find Plate Block of 4 of which we have seen only two in many, many years.