U.S.P.S. Souvenir Pages.
Massive accumulation of more than 2,700 U.S. Postal Service issued Souvenir Pages, huge range of issues, some duplication though not more than a few of any single issue, Scott Specialized Catalog lists these issues (SP1-SP1631) with prices ranging from $3.25 to $75, assembled by a diligent collector who sought every new U.S.P.S. issue for decades and unpicked for better values, Scott Retail more than $16,000.00