(written from a Production point of view)
James Gruzal (4 January 1938 – 3 July 2022; age 84) [1], was the stage name for James A. "Jim" Gruzalski, the actor who appeared as Don Juan in the Star Trek: The Original Series first season episode "Shore Leave". He was not credited for the role. He filmed his scene on Thursday, 20 October 1966 at Africa, USA. [2](X)
In 1961, while as a junior studying industrial art at University of Illinois, Navy Pier, Chicago, Gruzalski worked as a part time model and a military policeman in the Illinois National Guard. He was selected to portray a Navy shore patrolman in his first television appearance on the second episode of the twelfth season of the Jack Benny Show. ('Area Collegians Earn Spot On Jack Benny TV Show and Win De Paul U. Scholarship', Berwyn Life [Berwyn, IL], 11 Oct 1961, p. 16.)
Gruzal later worked under the stage name, James Gruzal, and in addition to his appearance on Star Trek, also appeared on The Munsters (1964, with Paul Baxley) and the film John Goldfarb, Please Come Home! (1965, with Barbara Bouchet, Terri Garr, Carey Foster, Lou Elias, Billy Curtis, Irene Tsu, and Glenn R. Wilder).
In 1970, Gruzalski became better known for being the third husband of 'A'-list actress, ten years his senior, Barbara Rush– her first being Jeffrey Hunter. At the time of their marriage, the six-foot-six Gruzalski, sometimes known as Mr. G, was recognized as being a West Coast sculptor who also worked an inventor, having invented a wheel chair for paraplegics that could go upstairs. (Eleanor Page, 'Barbara's Night', Chicago Tribune, 17 April 1971, p. 127.)
Two years later, Gruzalski was the scenic designer for the play "Some People, Some Other People and What They Finally Do", at Theater West/Club Theater in Los Angeles. (Dan Sullivan, 'Comedy Edged By Blackness', The Los Angeles Times, 27 November 1973, p. 65)
Gruzalski later divorced Rush, and during the mid to late 70s, began acting again, credited under his given name, where he made a handful of television series appearances as an actor, appearing on The Rookies (1975, with Carl Byrd), Police Woman (with Charles Dierkop and Joseph Campanella), Barnaby Jones (starring Lee Meriwether, featuring Walker Edmiston), and Starsky and Hutch (starring David Soul, featuring Gerrit Graham and Arthur Tovey) (all 1976). His final television appearance was as himself on the game show Tattletales (1977), where he was partnered with then fiancée, Lee Meriwether; the two later broke off the engagement.