I hate to be the bearer of possibly bad news, but many years ago there was a film being made at Battersea Power Station, I used to sell compounds like jewellers rouge, sizel wheels, polishing compounds etc, one of my customers was a metal workers/forge.They had been given a contract by the Films producers to make about 500 aluminium mills bombs, I saw them on the casting tables, and they were sent out unpainted, each one had PRAC on the bottom as per instructions and had ring pins and spoons, I even tried to get one from the owner of the business but it was a no go, It seems too coincidental that these are ally and have PRAC on the bottom as did yours, hope thats helpful