1970 (S) Lincoln Memorial Cent - Proof Large Date - Repunched Mintmark RPM-004

Description

Transitioning from business strikes to proof coinage, RPM-004 on the 1970-S Lincoln Memorial cent documents a Proof Large Date variety with the secondary S mintmark displaced to the north — S/S North. Cataloged under obverse die variety ODV-025 with die markers UVC-944 and DMR-006, this variety confirms that San Francisco's proof dies received the same hand-punched mintmarks as their business-strike counterparts and were equally susceptible to repunching errors. The proof striking process itself did not prevent or correct mintmark misalignment: by the time a die reached the proof press, its mintmark was already permanently embedded in the die steel from the hand-punching stage. Three die stages have been documented, tracking both obverse and reverse surfaces. Stage A presents both surfaces at Early Die State, capturing the proof die's crispest impressions when the combination of polished die surfaces and the northward repunched mintmark creates maximum visual contrast. Stage B at Mid Die State records the onset of die fatigue, which on proof dies manifests differently than on business-strike dies — proof dies lose their mirror finish gradually, with the fields developing a progressively satiny texture as striking cycles accumulate. By Stage C at Late Die State, the die has reached terminal condition. The northward displacement mirrors the direction seen on business-strike RPM-001, though the two varieties originate from entirely different working dies.

Die Markers

• UVC-944
• DMR-006
• Stage A:
• Obverse and Reverse are EDS
• Stage B:
• MDS (unconfirmed)
• Stage C:
• LDS (unconfirmed)

External References