What I've seen recently was a K frame with 2 slots along either side the front sight. Any pic's of factory ports from the late 1980's to mid 1990's would be a help. Didn't know S&W ported guns, thanks.
Certainly not one of SmithNut's absolutely outstanding K Frames, but here's a factory ported J Frame Model 460 Performance Center Centennial Airweight that I recently acquired.