This gun is filed up exactly like a bar in wood Purdey of the 1880's; the only difference being the trigger plate extension. The hammers, locks, and fences are Purdey all the way. Just the last 2 didgets of the serial number show on the photos of the bottoms of the barrels. With this entire number, a quick check against Purdey's numbers of the period and their records for that number should be conclusive.
Allt he best, Mal