To make sure, just contact SMITH/WESSON , they bought out T/C they will tell you all info.
The Armor Alloy Contenders were made from early 1985 to early 1989. Your frame was one of the last, made in early 1989. As has been stated previously, they have a slightly smaller hinge pin hole due to the coating used. T/C Custom Shop (Fox Ridge Outfitters) shop used to modify the frames to be compatible with blued barrels, but they were shut down with the purchase by S&W. The lack of cross compatibility and T/C getting stainless steel frames figured out killed AA.
The stainless frames were for the most part the "angry cat", but there are some Cougar on the Rock stainless frames out there.