Later in Macdonald Hastings book along with a picture of the Purdey it states.
"In 1870-the date is arguable- Purdey introduced this double-barreled 12 bore pinfire gun. It's importance is that this seems to be the earliest model showing the top lever and sliding bolt action which is basically the Purdey gun today. Collectors should be very carefull in assigning diffinitive years to improvements. The Purdey action is incorporated in a later patent (no.397 of January 1878) and described again in Beesley's patent of 1880".
