Blunderbuss identification

[Libertymarkone]

A friend received this blunderbuss as a Christmas gift. Supposedly it has been a wall hanger for more than 50 years. The only markings are on the barrel, nothing on the lock. It looks original except the stock looks more like oak than walnut. Thanks in advance for any help.

 

[Dave Wallis]

Pop the lock off and do some photos so we can see how well the lock has been made, also a photo of the left side of the gun would be good. If you're feeling competent, remove the barrel and see if there are any proof markings. Nice looking piece that's had a busy life!

 

[Libertymarkone]

Thanks for the suggestions, but it’s not my gun. Given the general level of corrosion, I don’t want to risk disassembly.

I did a little research, and the top mark on the barrel looks a little like a Birmingham proof mark. The lock’s exterior has so much corrosion that I can’t tell if there are any markings or not.

 

[Conquerordie]

That barrel seems rough for a British piece. The cock is funky too, something doesn't seem right. What is that under the lock, looks like metal wire or a sling swivel that is unattached? That's the fun with these guns, solving the questions!
Greg