Air Post stamps. 1933, Zeppelin issue, 3L-20L, complete set of six, blocks of four, most with sheet margins, 15L has slight gum foxing, full OG, NH, VF and scarce multiples, each stamp signed by Dr. Bolaffi, his certificate for block of 3L is included, C.v. $5,160++, Sassone #PA22-27, €12,500, Est. $1,500-$2,000 (Image)