Air Post stamps. 1927, black Airplane and ''Poste Aerienne'' on Coat of Arms of 1909, 1c-30k, complete set of 16 with additional black ''Specimen'' overprint, fresh condition, full OG, mainly LH, VF, each stamp with expert's sign, Persiphila #740-55, C.v. $1,650 for ''Specimen'' overprint, Est. $500-$600 (Image)