IIRC the 'New Frontier 22' didnt have the 'Scout' name too, the 'Frontier Scout 22' being the earlier version, fixed sight, alum. or Zamak frame (and the 'Peacemaker 22' was the case colored steel frame version of the 'Scout').
The Colt's Staglite grips were optional, but should have the Colt's medallion, so yours are likely aftermarket and may be 'marked' on the inner surface. The New Frontier 22 black plastic ones have an eagle molded in at the base as well as the rampant colt in an oval in the normal medallion location, and 'checkering', if you go looking for a set, but feel skinny compared to what you appear to have. I cant remember if they were available as 22 Mag only.
FWIW, Ive had my '74 NF for quite some time and have had, until recently a 3 screw Ruger SS and still have a SSS convert.; the Colts is more finely fit and finished. They are a nice revolver, good choice! As to value, like anything, what you and the seller agree upon. I use GunBroker as a guidline, not so much asking prices because a high ask with no bidders tells nothing more than its overvalued to the seller. If you got it for no more than the price of a used Single Six I believe you did well.
G1663xx is 1976 production according to my R.L.Wilson pocket guide.
I have the 22Mag cylinder in my Ruger now, and like it, considerably more 'thwack' with the WW Dynapoints (45gr. flash plated lead HP/ chrono 1500 in my carbine, dont know about the revolver) that I use for 'walkabout most of the time. Give 'em a go.