You see all kinds of Machine Doubling and Die Deterioration Doubling in the PL and Specimen sets from 1975 through the 1980s and 1990s...
"Discovery follows discovery, each both raising and answering questions, each ending a long search, and each providing the new instruments for a new search." -- J. Robert Oppenheimer
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Content of this post is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. See: http://creativecommons.org/licenses...0/deed.en_US
My eBay store























