Wild_Weasel: You said: "At this point a note on brass is important, Winchester and Starline brass is made specific to the 38 S&W and will only chamber in revolvers manufactured for the 38 S&W, while Remington 38 S&W brass/ammo will actually chamber in a revolver designed for the 38 Special (slightly smaller case diameter). The Winchester brass is noticeably thicker than the Star brass, causing a slight bulge if seating bullets too deep, while the Starline brass, with less internal taper, does not manifest this problem".
Are you saying the Winchester and Starline brass will not chamber in the 380 Webley?

? Rather than modifying the revolver front sight, can you obtain dies for the 380 (if different from the 38 S&W) and size the brass to fit the 380 chambers?

? Anything on the 38-200 that would help?

I had previously thought a charge of 3.2 gn of Unique under the 200 gn 38 S&W/380 slug duplicated the 600'/sec loading of mil-spec velocity? Your 3 gn load under a 158 gn slug is very mild - even the mil-spec loads are very mild for that matter.
You got me laughing a bit with your statements "Corbon and Buffalo Bore, stand aside" knowing their loadings and the original mil-spec loads for the 38-200 are at the opposite ends of the velocity spectrum but that older round has history, experience and battlefield experience the others do not.
Folks laugh at the 'anemic' loadings of the old 38-200, completely forgetting it shoots through the other guy at 25 yds. Not too shabby of the old and slow group..................