The Standard Catalog of Smith and Wesson (SCSW) will have pretty much all the available information about your pistol that's in writing.
I can tell you that your pistol was probably built circa 1993 or so (it may have been a little earlier; it WAS almost 20 years ago and I was sort of there). At this time S&W went through a period known as the "gun of the week" when they literally had 40 different models announced during the year.
They actually had a wheel looking device where you could "look up" a model number AKA "the whiz wheel":
The Gun Zone -- S&W Whiz Wheel
"Rare" IMHO is a relative term. I thought at the time they might have made as many as 2000 of each special model, but I really don't know now.
I will point out there was a recall on the decoker models (all the ones with 2 or 3 as the third digit in the model number). There should be two dots stamped under the decocker lever if the work has been performed.
I hope this helps,
Charlie