VERY FINE. A RARE MINT NEVER-HINGED COMPLETE SHEET OF 100 OF THE 1938 $1.00 PRESIDENTIAL ISSUE WITH "USIR" WATERMARK.
According to The Prexies by Roland E. Rustad, the printing of the $1.00 on "USIR" double-line watermarked paper intended for revenue stamps, occurred inadvertently, probably in 1950 or 1951. It marked the first time since 1916 that a U.S. postage stamp was issued on watermarked paper. The variety was first discovered in 1953 and the earliest documented use is May 9, 1951