Stone was certainly one of those, "Oh, THAT guy!" actors. The type of solid dependable supporting actors who can really add to any film or tv program. He did appear at the marathon for both showings of SOYLENT GREEN (SF/2 and SF/23). His other SF credits include appearances on the original OUTER LIMITS, plus LOST IN SPACE, THE INVADERS, LAND OF THE GIANTS and THE SIX MILLION DOLLAR MAN.
And, check out the number of classic TV shows he appeared on (often multiple times): ALL IN THE FAMILY, MASH, L.A. LAW, HILL STREET BLUES, QUINCY ME, BARNEY MILLER, BOB NEWHART SHOW etc etc.