There's a guy making a "headspacing plate", or something like that, for Webleys converted to .45 ACP. I don't know if it's just supposed to sit on the back of the cylinder, held in place by chambered cartridges, or if it's supposed to be soldered onto the cylinder, or what?
For a gun that's going to be shot, I'd much prefer the ACP conversion, so I'm not sure why someone would want to use the plate to convert the gun for use of obsolete, relatively obsure Webley rounds.
My S&W 2nd Hand Ejector has been fitted with a M1917 cylinder, achieving the same effect as shaving the original cylinder, and I wouldn't want to convert it back (I'd rather get a .452" barrel!).