This is an incomplete reverse hub trial, in copper, of just the eagle used on J80-J81/P87-P88. It is unclear whether or not this is an 1838 product or not. This hub may have been completed in the 1860s to produce the restrike patterns listed above.
This die trial, part of the Mint Collection at the Smithsonian Institution is unique and is also illustrated as figure 82 on page 40 of the "History of the National Numismatic Collections" by Vladimir Clain-Stefanelli.
Photo courtesy of the National Numismatic Collection of the Smithsonian Institution.