Callaway Went Thataway (1951)

"M-G-M's new comedy hit!"

Two smart marketing people resurrect some old films starring cowboy Smoky Callaway and put them on television. The films are a big hit and the star is in demand. Unfortunately no one can find him. When a lookalike sends in a photo, the marketing team hires him to impersonate Callaway. Things get sticky when the real Callaway eventually shows up.