1988 36¢ Air Post - Igor Sikorsky Mint Plate Block

United States #C119 36¢ Air Post - Igor Sikorsky Mint Single Mint condition, never hinged.

United States #C119 36¢ Air Post - Igor Sikorsky Mint Sheet of 50 Mint condition, never hinged.

United States #C117 44¢ Air Post - New Sweden Mint Plate Block

United States #C118 45¢ Air Post - Samuel Langley Mint Plate Block Mint condition, never hinged.

United States #C49 6¢ Air Post - Air Force Mint Plate Block