Proofs should be found on the bottom side of the tubes now hidden by the forestock. Neither Brit nor Belgian would surprise me. Those tubes were made in Europe and were proved there. By law they must have been so stamped.
A true Westley Richards will always be marked as such. Birmingham as I remember had several legitimate makers by the name of Richards. Never just an initial nor a single name for a Westley Richards. None approached Westley Richards for quality.
"London Fine Twist" is a further indication of a trade gun. Twist is one of the least expensive types of damasc construction. Basically a ribbon of iron and a ribbon of steel twisted together and welded to form the tube. If an English gun it was almost certainly not produced for domestic use as makers seldom if ever stamped their product in such a manner. Trade items, though, often carried this stamping.
If a Belgian gun, then almost anything goes. Let's just say the Belgians had a way with words... Anything to make a gun seem attractive to a potential buyer. They'd commonly use "London Fine Twist" to confuse the issue at hand.
The fact that the gun is still in use doesn't really surprise me. Damascus tubes don't usually fail quite the way we sometimes think. They usually bulge slightly, then begin to "unravel" for the lack of a better term.
USUALLY. If the tubes have been well cared for and loads have been kept moderate using only black powder, then I'd expect them to still be sound.
For myself I'll stick to my L.C. Smith doubles with fluid steel tubes. Laminated tubes are from another era and technology. But, again, it's just my opinion and others feel differently.
Value? We don't do that here. I'd suggest a trip to <Antiqueguns.com> for that answer.
