JDW, your appreciation of quality and mine clearly differ. But rather than get engaged in that - i'll restrict my like for like comparisons to what we can see.

I suggest you look at the first photo you posted and compare that with the Edward Lang on a quality basis. Then look at the Joseph Lang backlocks and compare those with the one you just posted. In each case, there are comparisons, which on point by point basis favour the two Langs, but the ball park is (quite) close.

Then look at the Woodwards and the Purdey hammer gun (the case coloured one). You SHOULD be able to see a qualitative step up. A big one.