Another "Moore"

[Robin_G_Hewitt]

I really did think I was buying a Belgian blunderbuss. It was clearly marked, "Moore". "London". I mean, How Belgique can you get, it's practically Fabrique Nationale?

I ask the dealer if it had London Proofs and he said, "There are no proofs on the top of the barrel".

Knowing winks might have been exchanged were there eye to eye contact.

It was just so pretty I couldn't resist. Today it arrives, out comes the barrel revealing B'ham proofs and a crown over T.

Are the Belgian clones getting hard to find

[Robin_G_Hewitt]

There is a missing screw. I pulled one from my other blunderbuss and I can see why it is missing.
Pressing BlueTack in to the better preserved female thread suggests 1/8" 36tpi so there are two possibilities.
I would guess Whitworth if it was percussion but his standard was not until 1840'ish.
I can't be the first, so do I start filing a Whitworth 55 degree or a UNC 60 degree?