Use "groovy" fonts like Cooper Black or Bauhaus 93 . Incorporate colors like avocado green, harvest gold, and burnt orange to match the Escape from the 70's aesthetic . Physical Props (Paper-Only):
Use a drawing of a cassette tape where the "ribbon" (the tape visible at the bottom) contains a sequence of numbers or letters that need to be decoded. Escape.from.the.70s.rar
Use a fake 1970s newspaper front page with circled words that form a sentence. Use "groovy" fonts like Cooper Black or Bauhaus 93