There is one set of a Dime, Quarter and Half struck by Martha Washington dies that are permanently housed in the Smithsonian Institute, embedded in blocks of lucite. According to United States Pattern and Related Issues, by Andrew W. Pollock III, “the only trial pieces purported to have survived metallurgical testing in 1965 were the Dime, Quarter Dollar, and Half Dollar equivalent strikes in copper-nickel clad over copper.”
My discovery of the Martha Washington Test Piece on a copper-zinc Cent planchet struck 10% off-center with a uniface reverse was a front page Coin World article on August 7th, 2000. In a response to the Martha Washington Test Piece that I discovered, the Mint announced that “the dies are available to the Mint’s metal and blank vendors for testing.”
This is a Martha Washington Half Dollar. It is listed the 9th Edition of the Judd book as #2132. This piece was also certified by NGC as a half dollar-sized test piece graded MS 63.