JA
As it was 1974, when not many people had VCRs, and only broadcast in one city (as it was a local news show), it's very unlikely there was ever any recording made other than the studio master. Not like when Budd Dwyer shot himself on live TV 13 years later.
Nothing stopping an off-air recording popping up though, but I'd like to think it would've surfaced by now if that was the case.
As it was 1974, when not many people had VCRs, and only broadcast in one city (as it was a local news show), it's very unlikely there was ever any recording made other than the studio master. Not like when Budd Dwyer shot himself on live TV 13 years later.