The information below is primarily excerpted from Pollock and from the August 30, 1993 and September 6, 1993 issues of Coin World by Kenn Henderson. This metallurgical trial was produced by the International Nickel Company in 1964. They were one of several companies the U.S. Mint commissioned to find a suitable alloy replacement for silver. The obverse features a bust of Dr. Paul D. Merica and the reverse features his laboratory where the pieces were struck. The design was created by Gilroy Roberts and the hubs were created by the Medallic Art Company. The coins were issued in sets with a quarter sized coin P5340 and a half dollar sized coin P5375. Examples were struck as follows: P5333 50% nickel, 50% copper with plain edge. An example sent to NGC has 098-22 engraved in the right obverse field. P5334 50% nickel, 50% copper with reeded edge. P5335 95% nickel, 5% silicon on a permalloy core of 79% nickel, 16% iron and 5% molybdenum with plain edge. P5336 95% nickel, 5% silicon on a permalloy core of 79% nickel, 16% iron and 5% molybdenum with reeded edge. P5337 96.8% nickel, .4% iron, .24% chromium and 2.56% undefined alloy with plain edge. These should be magnetic according to Roger Burdette. P5338 96.8% nickel, .4% iron, .24% chromium and 2.56% undefined alloy with reeded edge. These should be magnetic according to Roger Burdette. Image courtesy of Saul Teichman.