A couple of shows from 1973 or 1974 I believe are out there, as is definitely NBC show no. 2000 (with Mel Brooks guest-starring as his 2000-Year-Old Man character) and the 1/3/75 finale. An episode from the syndicated nighttime show (1974-75) is out and about as well. The 1978-79 series may have an ep or two out there.
There are at least five episodes of the late '70s version out on the trading circuit, including the premiere, second episode, 11/13/78, 1/16/79, and the finale. There was a Tournament of Champions despite the short run, and a partial episode from that also circulates. However, this run is seen as the "red-headed stepchild" of the franchise due to the highly disliked elimination format. Our best hope for finding episodes at this point from the original run is via audiorecordings, and even that is where a bunch of episodes from the first season of the current run are sourced from in the J! Archive. The 5/2/68 episode circulates from an audiorecording. A tape trader recently found an episode not listed there from December 1984 from an original broadcast, and the J! Archive is around 80% complete for the first decade or so of the show, so much of the Trebek run remains quite intact, but tape trading would be a big assistance, especially for episodes prior to the mid-2000s which aren't regularly shown on Pluto.
A neat idea for a possible special episode is that since there are 61 clues total in a game, have each clue in that episode be related to a different year in the franchise's history, ranging from 1964 to 2024. Sure, there were no shows in 1976, 1977, or from 1980-1983, but board games were readily available during those gaps.
