that top pair with the "wide" wood, behind the medallion washer and being 1 7/8 appear to be N frames.................."L" frames came in many years later after those "diamond" escutcheon panels,,,,,and yes, "K" and L are the same size, the "L" frame was to make it a true 357 frame instead of being built on .38 special frame, good move on S&W's part, BUT the hey day of the LE and need for more firepower ( round capacity) took over.....one thing the "urban" riots taught us back in the late 60s
Model 19 was my first duty gun, and the newer "L" frames made it even better
Jussbad, the same appears to be for your stags, the material behind ( to the rear of the black spacer) is wider, like an "N" frame type......