Bidspirit auction | Liechtenstein - Air Post stamps

Liechtenstein - Air Post stamps - 1930, Airplane over Mountains and Vaduz Castle, 15rp-1fr, complete set of six, in addition black surcharge 60rp on 1fr lake, fresh quality, full OG, NH, VF, C.v. $648, SBK #F1-6, F16, C.v. CHF970, Est. $180-$240 , Sc. #C1-6, C14