i reckon they were introduced around 2002/2003. but wilson still have the triad technology in some of their current frames. the most similar to your current racket would be the k5, which comes in 2 headsizes (108 sq inch and 98 sq inch) and weighs around 270g.
Wilson Triad tennis racquet are now replace by the nCode and K Factor technology introduced by Wilson which can produce more power and stability than the ordinary racquet. So we cant find the new Triad racquet anymore.
Is it really true that Triad more stable than your Prince o3?
You can look for new Wilson K Factor or nCode(Cheaper) racquet to replace the Triad.