Before his acting credits, Holland was the model for Fawcett Comics' fictitious faux B-Western cowboy Bob Colt, that ran for ten issues in the early 1950s. But his best-known model role was for artist James Bama's illustrations of the character Doc Savage used on the covers of the paperback reprints of the 1960s. Bama called him "the world's greatest male model." His facial features were also used in the 1970s reprint of the original pulp The Avenger novels. Holland was also the model for Mack Bolan of The Executioner novels.