Bought a finished French Type D, brass hardware, jug choked 20 gage from Caywood in November. Haven't been able to shoot it yet but impressed by fit & finish. Lock sparks beautifully.
Can't comment on authenticity, 41-1/2" barrel.
I found Dan Caywood quite personable. Well, maybe I can't tell if someone has an attitude or is arrogant, as I have been described in such terms. I generally take it as a complement.
I like the Caywood for shooting as he uses actual Gun Barrel quality 1137 modified for the barrels, says he buys his blanks from someone who supplies to modern shotgun makers. When all is said & done, what GBQ means, hopefully, is that the mill has taken care specifically to avoid any seams or cracks in the bar, and that each bar has been inspected against seams. I have been involved in getting a definition of GBQ 416 at my former employer, for a US rifle manufacturer. Any steel, stainless or expensive nickel alloy has some small percentage of bar with some defect in it. "Small percentage" is no comfort to those on the wrong end of statistics.
Am slowly putting together a Caywood pistol kit bought from Northern Rifleman. Again can't comment on how it compares with others because I've not touched a file or chisel for decades, when I did I made from the plank. Kit seems fine to me, though. Lock sparks well, looks well machined & finished inside.
I do not know what Chambers uses for barrels, maybe the same thing. Or, maybe just screw machine stock, 12L14, as it machines so well. I personally don't care to wrap my digits around a tube of such metal. Sorry guys, I'm a metallurgist with some successful experience as expert witness in a couple cases where the shooter got crippled, not by his own fault.