Michel 868-869 - Native flowers, 1948, first day cover, first day long postmark

Austrian first day cover with the stamp values 10+5 groschen and 20+10 groschen from the "Heimische Blumen" series on a large first day decorative envelope from 1948, the stamps were cancelled with the rare first day long cancel on 14.05.1948 in Vienna, the envelope was folded in the middle.