The Murray BMX rabbit hole is largely void of this bike, but I learned a lot about their BMX team and the bikes they rode. It was no surprise to learn that largely over the years that Team Murray existed, many of their top riders rode re-branded frames of their choice instead of Murray's mostly fragile offerings. The only clue I can find so far on this bike is from a moped enthusiast website that declares 1977 was the year Murray introduced their BMX models:
Youth bicycle production received a boost with the 1965 introduction of Murray’s version of the small-tired, banana-seat, wheelie bike pioneered by Schwinn, the Murray Wildcat. The Wildcat was also styled by Schreckengost, who gave it his own interpretation of a chopper motorcycle, with high-rise handlebars, a tall sissy bar, and a flared rear fender. A series of models followed, including the Eliminator, Firecat and Hotshot. In 1977, again following a youth trend, Murray introduced its BMX model.
A 1977 Murray catalog could solve the whole thing...