The existing LarryKert.com archive records Kert working as a stunt double and stand-in while still young, before his theatre career.
Kert was known as a gymnast and horse rider—skills consistent with the highly physical career that preceded and accompanied his musical-theatre work.
The old site records 1,214 performances of West Side Story before he left to promote Larry Kert Sings Leonard Bernstein.
The Tony Awards still state that Kert is the only cast replacement ever nominated in a competitive Tony category, for Company in 1971.
Kert and Carol Lawrence performed the West Side Story balcony scene and “Tonight” on national television on 2 November 1958.
The NYPL biography identifies Kert's 1990 Rainbow and Stars reunion with Carol Lawrence as his final public performance.
On 21 May 1989 Kert appeared in Cole Porter's Nymph Errant at the Theatre Royal, Drury Lane, in a performance recorded live.
Kert's elder sister Anita Ellis became a prominent vocalist and is remembered especially for dubbing singing voices for film stars including Rita Hayworth.