In 2012 I found a 2" 15-4 as the lone revolver in the case of a LGS that specializes in "tactical weapons". I asked the owner about the gun and was advised a retired police officer traded in his old back up revolver for a Glock. The shop owner had a $300 tag on it and we settled on $265 out the door. Like yours, I consider this one of mine fairly pristine and it came with a Tyler-T adapter and nice holster. This was my second Model 15; the first being a 4" 15-3 (my very first S&W) purchased a year earlier.
Both are accurate and I really enjoy taking them to the range. In my hand the 2" shoots groups as close as the 4" on the self defense range. The original magnas are stored away and currently the gun has faux pearl magnas with the black Tyler adapter. Looks great. This is one of those treasured Smiths that will be a forever keeper. The serial 75K5678 dates to 1980 I believe.
I hope you enjoy yours as much as I have mine.