Salopian, I recall Geoffrey Boothroyd having a Lisle over/under shotgun so may have mentioned it in connection with that. I'll have a look through his book on O/U's again but I would have remembered if he had solved the tiger mystery. I am off to Derby library in the near future to do some research on that and another gun that turned up marked Derby Gun & Cartridge Co., Derwent St. Derby. Just need the spare time now. Thanks. Lagopus.....