Additional theatre credits include Goodtime Charley (in which he sang a duet "Merci, Bon Dieu"; and for which he received Tony and Drama Desk Award nominations), Fools, The Front Page, A Flea in Her Ear, and Victor/Victoria.
Shull's screen credits include thirty movies, The Anderson Tapes (1971), Klute (1971), Slither (1973), The Fortune (1975), Splash (1984), Garbo Talks (1984), Unfaithfully Yours (1984), Housesitter (1992) and Private Parts (1997).
His television appearances included Love, American Style in episode "Love and the Locksmith", Ironside "Once More for Joey" aired 1974, Good Times "The Visitor", The Rockford Files "The Great Blue Lake", Alice "Flo's Chili Reception", where he played Mel's rival restaurant owner Barney of Barney's Burger Barn; Diana co star, Lou Grant episode "Samaratan", Hart to Hart, and Holmes & Yoyo starred as a police detective, as well as numerous television movies.
"[3] In 1995, Shull co-founded the North American Araucanian Royalist Society (NAARS)[4] with Daniel Paul Morrison.
The NAARS devoted a large portion of issue number 10 of their official journal, The Steel Crown, to the life of Shull.