Claim: Leonid Kinskey was Professor Overbeck in the Batman TV Series' episodes 35 and 36 in 1967.
Evidence: Jan 4th 1967 Batman (TV Series) Professor Overbeck Episode: 35, Series 2, "The Contaminated Cowl" Jan 5th 1967 Batman (TV Series) Professor Overbeck Episode: 36, Series 2, "The Mad Hatter Runs Afoul"