Stamps of PANAMA
Air Mail Varieties
Sa-4a Inverted Overprint
Sa-4b Doubled Overprint
Sa-5a "Aereu" for "Aereo"
Sa-5vc Inveted Surcharge
Sa-3v Varietals
Extra ink under "E" of centesimos, probably from heavy ink.
Extra ink above "M" of centesimos, probably from heavy ink.
Extra ink above "O" of centesimos, probably from heavy ink.
Sa-5vb Doubled Overprint