These were struck for Frank Zinkann by the Pressed Metal Products Company as a pattern for the 1987 Constitution Bicentennial. These are strictly a private enterprise not authorized by the Mint and thus should not have been put in Pollock.
Examples were struck as follows:
Gold P5450 with supposedly only 6 pieces struck, illustrated above. Click on the thumbnail to see an enlargement.
Hafnium P5455 with supposedly only 2 pieces struck, illustrated below.
Palladium P5458 This is not in Pollock, we have assigned it a number based on Pollock's listing these alphabetically. An example was offered as lot 1581 in Numismatic Auctions LLC's 12/14 sale.
Silver P5460 with supposedly only 100 pieces struck.
Tungsten P5465 with supposedly only 80 pieces struck. These show extremely weak strikes due to the hardness of the metal as shown below.
Photos of the gold and tungsten examples are courtesy of Heritage. Photo of the Hafnium example is courtesy of Bowers and Merena