Michel 226y Type II-II-I – Airmail stamps, 2.50 crowns, strip of 3, 1918, mint

Austrian stamp 2.50 crowns from the stamp set ‘Airmail stamps for the Vienna-Krakow-Lviv-Kiev route’ as a strip of 3 in the sequence Type II, Type II and Type I from 1918. Colour change of previous crown values with overprint FLUGPOST or value overprint, intaglio printing, line perforation 12½