U.S.P.S. Commemorative Panels.
Vast treasure trove of more than 1,450 U.S. Postal Service issued Commemorative Panels, issues range from 1970's to present, some duplication though not more than a few of any single issue, all are in their original protective packaging, Scott Specialized Catalog lists these issues (CP1-CP810) with prices ranging from $6.50 to $40, assembled by a diligent collector who sought every new U.S.P.S. issue for many decades and unpicked for better values, Scott Retail more than $17,000.00
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