Austria: Aerogramme Used as a Local Special Delivery Letter

Austria (Greiner #7b - greenish-gray overlay on light grey paper) used as a local special delivery letter within Vienna on April 10, 1958.

Aerogramme type designation crossed out and "Par Avion" routing instruction obliterated with special delivery label.


Reference
Greiner/Greiner,  Aerogramme von Europa, 3e. 1993