With a post like this 2 above yours,Possible Counterfeit
A letter and provenance from the Father.I have a letter from S&W stating it was a trial run to test the market
with a 3" and that only a few hundred where manufactured.
I would request a letter from Roy Jinks, the Smith & Wesson historian and recognized last word on all things S&W concerning this most unusual revolver, unless that is the "S&W letter" you already possess. Do not sell it. Get a good appraisal or two from disinterested collectors first. I agree on the $1000 and up, with a letter from Roy.
The trigger DOES look like a late model MIM version.