Here is an image of an epoxy resin "plaster" that shows only the main device of the coin it was used to make, the South Korean 10-Won (Fourth Series, 2006-date). Is there a specific name for such pieces?
Galvanos were important parts of the die-making process, but galvanos are metal (they use a galvanic current to produce an electrotype.). Read more here: https://www.coinbooks.org/v20/esylum_v20n14a12.html Intaglio is a process for making prints. The design is cut into a plate, ink is run across it, and then it is used to make the design. Intaglio is used for paper money. Read more here: https://en.wikipedia.org/wiki/Intaglio_(printmaking) As far as I know, there is not precise term beyond "plaster mold." The plaster mold would then be used in the reducing machine to make the master hub, which would then make master dies. Many modern mints skip the plaster mold step nowadays and design using a computer software. You can read more here: https://www.phelimint.com/blogs/learning-centre/creating-a-coin-die-turning-art-into-a-mold https://www.usmint.gov/learn/production-process/die-making
Jason, it was a working copy of the Seal of the President of the United States. It was 32-1/2" in diameter. My brother was dispatched by the Smithsonian at the behest of President Reagan to recreate a copy of the original that was in the Capitol. When he finished, the copy was then mounted in the White House, and President Reagan allowed my brother to keep the working copy. My brother gave it to our father who was a big Reagan fan. When our parents passed, my brother didn't want it, so it fell into my hands.
