In 1990, the factory was producing a special series of revolvers for Ellett Brothers, called "12 Revolvers", with a different model for each month of that year. One of these guns was a 8 3/8" nickel M14, like yours. The drawing below is of the M14 that was known as "The Last Stand" model.
The 12 Revolver series was not very successful and not all originally envisioned sets were completed. Lots of individual guns were shipped, as well as many guns that did not get the laser etching treatment. It's my belief that your gun was part of the production for that model, some folks here have examples and it's been discussed before. The two key points that lead me to that conclusion is the nickel finish and the front sight, which are part of the specs for "The Last Stand" model. The only thing about your gun that I'd question - assuming it was part of the 12 Revolver production - is the grips, the original M14 - The Last Stand - had more traditional S&W Target Grips. I do not recall any M14's having been shipped with the smooth Combats as in your picture, but I could be wrong.