Auction 265th - 273rd - Day 5

1927 (Nov 11): First Flight cover from Rustchukj to Kustendil franked by 1926 2 l. grey-brown, and November 1927 Airmail 1 l. in red on 6 l. blue on dull green and 4 l. carmine & yellow - this last surcharged in black (unlisted in Michel) instead of blue - all tied by "Rousse" First Flight cachets in black. Reverse with Sofia cds (Nov 11) and Kustendil arrival cds (Nov 12). File fold away from the adhesives, the error stamp signed by Vassil Karaivanoff and unique on letter. A very rare cover. Cert. Hitzler (2016).