Watch List notes:

George IV (1820-1830), Pattern Sovereign Struck in Copper, (182-), last digit missing, uniface, St. George and the Dragon, struck as a trial most likely at the same time of the 1821 Pattern copper Sovereign that featured in the Bentley collection (Marsh 5C, R7). This example unrecorded and probably unique. As struck, hints of orange lustre. Interestingly other denominations for 1821, like the silver Crown, also exist with copper proof strikings of great rarity. Perhaps they were final trials before committing to using more precious metal, in this case, the making of gold proofs of the Sovereign. Pistrucci would have had the right to strike special orders for coins, so it is even possible he acted upon a "VIP" commission to strike examples of certain coins in bronzed copper.