Los 398
1913, Airmail Laufen-Solothurn 50 c. green with additional franking tied by special cancellation "SCHWEIZ. FLUGPOST LAUFEN SOLOTHURN 28.9.13" and cds. to specially printed postcard (Borrer with his Ponnier-Hanriot monoplane), some very minor abrasion on the card, otherwise very fine, Marchand certificate
