The product code is for a stock standard 2 1/2-inch M686. They used that same pc right up to and including the -5. A purpose built Performance Center gun of this era would of likely had a pc that began with "17".
The s/n looks normal. Sometimes special guns will have unique s/n's, or certain distributor's will request special s/n's.
The Spec. Ord. number indicates a ship date of September 30, 1988. Which aligns with the s/n sequence. The earliest -3 M686 I've seen was from June of 1988, so yours is from the first few months of production of that dash number.
"RR" means the gun left the factor with a "Red Ramp" front sight insert. So the yellow/ivory color one it wears now is an aftermarket replacement. I have a ivory insert on a pre-Model 15 and really like it on that blue gun.
The "M" along the top of the label, I don't know. Could be an inspection mark, acceptance, or an inventory mark. Might not mean anything about the gun.
Sometimes there will be a Mag-Na-Port sticker under the foam liner of the box. I've seen that a few times. You should check and see if there's one there, but I don't think there's any doubt MP did the work. I heard at one point MP put the sticker on the outside of the box and S&W didn't like that. That's why they put their sticker under the foam. Probably an internet myth.
That stocks it has now are not original. Those laminate wood Targets are a fairly recent thing. A 2 1/2-inch -3 would of come from the factory with Hogue neoprene grips.
