The only hope here, as I see it, was ABC's onetime policy of routinely kinescoping its "live" shows (e.g., newscasts, soap operas - and game shows), which lasted up until about 1970. ABC ultimately junked its old kinescopes (except for the newscasts), but there may be a chance this episode is in the hands of someone out there. (If this had been an NBC or CBS game show of the 1960s, I'd be even more pessimistic.) Good luck.