Paul Roberts Rigbys were all built on original Rigby ( or Webley if you prefer ) action forgings as far as I know and have a reasonable claim to being `true` Rigbys. The subject of who produced `rough` action forgings is one that needs research but I`d give odds on them all being produced in Sheffield.
Lockmaking was a specialist art and nearly all - including the very best, ie. Joseph Brazier Ashes, Stanton and Chilton were built in Wolverhampton ( which sounds - and was - a lot worse than Coventry ! ) Locks by those three concerns were used by all the makers of `best` guns and occasionally you will find a London best gun with signed locks - I`ve seen four Holland & Holland Royals with signed Brazier locks now, one of them a rifle. After WWII the quality of some makers locks declined considerably which is why A.A.Brown & Sons started to build their own - which Robin still does. The next time you communicate with Robin Brown ask him where E.J.Churchill sourced some of their locks from immediately after WWII ( and ask him also about the O/U shotguns from a very famous name which were built in the same place as those locks ! )
I can`t imagine what you are referring to re. Westley Richards and A.A.Brown & Sons .......... it`s just a coincidence that A.A.Brown & Sons rented space in the Westley Richards factory after WWII. ( That photograph of a very young Robin holding an A.A.Brown built Westley Richards is a bit of a giveaway though ........... ! )
A third of Holland & Hollands were built by W.C.Scott and others up until the 1890s ? To my knowledge ALL H&H `Dominion` models were built by W.C.Scott/Webley and Scott and A.A.Brown were building Holland & Hollands in the 1950s.
This is beginning to look like an advertisement for A.A.Brown & Sons with the implication that they built guns for just about everyone. They certainly made guns for many other `makers` but were just one of several Birmingham `makers to the trade` some of whom probably never built a gun under their own name.
The heart of British gunmaking was Birmingham for around two hundred years yet it has laboured under a `second best` label for nearly as long. The extensive research that has taken place in recent years has revealed ( with more revelations to come ) that the `second best` label is not only inaccurate but ridiculous as many `best` London guns were actually built in Birmingham.
A new argument that is now developing as a result of those revelations is that most innovation took place in London - Oh yeah ? Look at the patents granted to Anson & Deeley and W.W.Greener - to mention just two concerns, both of whom were based in Birmingham........and I haven`t started on the provinces yet: Choke borings it is now pretty well accepted were invented by W.R.Pape in Newcastle; The trigger plate/round actions by MacNaughton and Dickson in Edinburgh - the list goes on and on.
Interesting that this thread has developed around a Scottish rifle carrying a Daniel Fraser `label` ( but built by Joseph Harkom/Thomas Mortimer - another example of `making to the trade`. )