20 US Airmail Plate Blocks - 20 Different Mint Never-Hinged

Airmail Stamps are generally produced in smaller quantities than definitive and commemorative issues. As a result, Airmail Plate Blocks are scarcer in today's market. Here's 20 Mint Never-Hinged Airmail Plate Blocks that represent almost 15% of all U.S. Airmail Plate Blocks ever released.