1991 40¢ Air Post - William Piper Mint Sheet

United States #C129 40¢ Air Post - Aviation Pioneer William Piper Mint Single Mint condition, never hinged.

United States #C128 50¢ Air Post - Harriet Quimby, Pioneer Pilot Mint Sheet of 50 Mint condition, never hinged.

United States #C130 50¢ Air Post - Antarctic Treaty 30th Anniversary Mint Sheet of 50 Mint condition, never hinged.

United States #C131 50¢ Air Post - Americas Issue (Bering Strait) Mint Sheet of 50 Mint condition, never hinged.

United States #C42 10¢ Air Post - Post Office Mint Sheet of 50