... they had recessed chambers ...
Neither of my M19-7 K-Comp revolvers has recessed chambers. These are over ten years old as I bought them before I moved to Georgia in March of 1995. I think I bought the first of my pair in April of 1994 after seeing it in a guncase for a few months. The serial number prefix on my pair is SDA01. On both of mine, the night sight insert is quite dim. It is about time to send them back to S&W for new tritium tubes.
These are Performance Center revolvers, having quite a bit of extra work in them. In addition to the expansion chamber, the enclosed ejector rod, and front night sight, the revolvers have a reshaped cylinder thumb piece, a profiled hammer spur, and a fixed trigger stop welded to the rounded trigger. The gold markings were not roll marked, and refinishing will eliminate them. How do I know? One of my pair has been refinished in NP3.
The K-Comp was a stocking dealer special, and a fairly large number were made. The F-Comp, basically the same revolver in stainless steel (an M66 variant), was made in much smaller quantities. The "F" denotes S&W's internal designation for the stainless K-frame. I am still looking for an F-Comp that was marketed right before the K-Comp hit the market.
I like my K-Comps but I do not like shooting them on an indoor range. The muzzle blast is extremely annoying due to the expansion port. I end up wearing muffs over plugs when I shoot mine. For a range-only gun, I would pass, preferring an M27-2.