The way I read the barrel rib on mine it has nothing to do with where the gun was made. It says the barrels are of "London Laminated Steel". The only thing on mine related to where it hails from is the Birmingham proofs. This of course does not say where it was made, only where it was proofed.
Lefever H grade barrels along with those of some other makers were said to be made of "London Twist". This I take not to mean they were fabricated in London but was meant as a description of the pattern. These barrels do not look anything like those London Twist barrels, these (both mine & the ones pictured) look like regular old Plain Twist or what is sometimes referred to as wire twist. They were of course not made of wire.