Willam Moore (the English one) was a first class Gunmaker and as such had his good name widely abused. I had one among a batch of scrap guns that I de-activated to make into safe wall hangers that was marked Wm. Moore and a London address that he had never traded from. The gun was a dreadful piece of rubbish but bore English proof marks; possibly forged. I would suggest that your friend treats his as just an interesting wallhanger as the condition looks rather poor to risk firing. Lagopus.....