He seems to appear in part of this film, in the library at LIncoln Center:
http://nypl.bibliocommons.com/item/show/12148696052907_robert_joffrey_ballet_(motion_picture)
Title: Robert Joffrey Ballet (Motion picture)
Publisher:1965
Characteristics: 1 reel. 30 min. 1080 ft. :,sd. b&w. ;,16 mm.
Notes: (U.S.A.: Dance. No. 3) Telecast on WNET-TV, New York. Executive producer: Jac Venza. Producer: Virginia Kassel. Director: Karl Genus. Author: Bo Goldman Opus '65: excerpt. Choreography: Anna Sokolow. Music Teo Macero. Performed by Margo Sappington, Richard Gain, John Jones, Ian Horvath, and Dennis Nahat.