Purdey guns 10528/9 were completed in 1879 and re-barreled in 1971. They are built om William Adam's lever cocking mechanism of March of that year, UK patent number 1128. William Adams worked for Purdey, Boss and Stephen Grant and patented six gun improvements between 1869 and 1897. He worked with John Robertson on the Boss single trigger, safety and ejectors and Grants son Samuel on an asymmetrical cocked helical spring gun. Adams lived south of the Thames in Battersea but typically listed his address on patents as that of his employee; Oxford Street for Purdey and St. James's for Grant. The old Grant address is the new home for H & H.