What you have to remember is the fact a Dickson Round Action was a premium luxury item - and a step above any London gun.
When Lord So-and-So wanted a round action built as light in weight as possible, that's what Lord So-and-So got. Price was not an object. So if the gun left the shop with .019" walls (I've seem them), that was fine. If the walls became too thin after a few seasons, and the gun was deemed to need new barrels when it came in for the annual overhaul, that's what it got. And Lord So-and-So paid for it (hopefully).
I think a lot of people today do not understand this was the way things were. Dicksons were not built for the po' folks.
Whilst I agree the majority of your post, I don't think the DRA was a 'step above' - more like the 'top step' shared with some London makers. Certainly not lower, but not (in my opinion) higher either.
