Legendary wrestler Ernie "The Big Cat" Ladd plays Rocky Johnson's manager here. In real life, Rocky Johnson was a face (good guy), and never had a manager.
The main characters attend a WWF wrestling card. In the time frame of the show the WWF was known as The World Wide Wrestling Federation (WWWF). It was promoted only in the Northeast. Wisconsin would have been part of the territory for the American Wrestling Association (AWA), promoted by Verne Gagne. The earliest WWF show in Wisconsin was held on April 18, 1985.
Rocky Johnson worked in the NWA in the '70s. He did not sign with the WWF until the '80s, and in the '70s it was known as the WWWF.
In the 1970s, wrestling was something that was very fringe entertainment, watched mostly by older people in certain markets (think: Archie Bunker). It was not something teenagers were interested in during the '70s.