Muff Pistol ID?

[Grendl]

Hey gang, the cool folks at one of my local antique stores asked me to help them ID a piece new to them. Looks to be a percussion cap, screw barrel muff pistol with a sliding trigger guard/safety. The barrel is not rifled and my belief is that it was supposed to be loaded with an over-sized ball behind the barrel which would be swaged when the barrel was screwed on to help achieve lethal muzzle energy.

I see no hallmarks, just engraved "London" and what appears to be "Blais" on opposing sides. It seems to function fine but someone took a wrench to the barrel at some point in the past.

Looks like it, or a remarkably similar pistol, was recently listed on GB with no bids. The second right side photo is intended to show how much the trigger guard slides back.

Anything else?

[pitfighter]

It's ghosting on Google as a past-auction from Gunbroker - (cannot access it as it's an old sale.)
I would hazard a guess a say it's the same pistol.

Price-wise - $250-$350 -

[Grendl]

God find Pit, she confirmed its the same pistol but they're still hoping someone knows more.