1915 Gatun Locks, 5c blue and black, center inverted, well centered, tied by violet "Agencia Postal Feb 23 1916 Panama" cancel on cover addressed locally in Panama City, additional postmark (arrival?) repeated on back, filing fold terminating in a minor cover tear at bottom, well away from the stamp, fine and rare cover, with 2007 Alex Rendon certificate (Cat No. 210a) (Image)

Est.$3,000

1930 return flight card from Panama (May 15), via Havana, Cuba (May 18) to New York City, where 65c Zeppelin adhesive was added (May 27) for further transmission to Friedrichshafen, v.f. and scarce mixed franking combination card (Image)

Est.$1,000