This is a reverse hub trial, in copper, for the 1838 Gobrecht design without stars J84/P93. It has not been available for viewing to determine if it is an original striking of 1838 or a later striking to test the die for the purpose of restriking the various Gobrecht dollar rarities made in the 1850s-1870s.
It is believed to be unique and is ex Lohr, Batchelder (see Numismatist 2/62), Kagin's 7/69, Kagin's 11/73, 95 ANA. The 95 ANA catalog shows the image as a die trial as opposed to the correct image in the Pollock and Judd books. Judd and Taxay incorrectly describe this as being struck in white metal.
Photo is a scan of the illustration in the Judd book.