Only one source I have encountered conveys the POTENTIAL high quality (fidelity) of the ORIGINAL Hoyt Curtin recording. They are the cues used in this mini documentary:
QUEST 16 The Incredible Music of Hoyt Curtin - YouTube (http://www.youtube.com/watch?v=j2mXxBMvfh0)

There are couple of very long and complete mp320 sources avail. (e.g. iTunes, and Incidental Themes 53-track album) but the quality of these purported newer masters is not as nice as the YT documentary above.

There was the Hanna-Barbera's Pic A Nic Basket Of Cartoon Classics -- Thread 100757 -- Disc 2 had the opening & end credits and nine minutes of underscore. There's a two-disc set floating out there called "File O37" that has lots of versions of the theme and also underscores. I haven't compared to see if there is anything different from the Pic-a-Nic basket.

Good luck! I'd like to hear more too!

Mark Alfred
Mark's Super Blog (http://markssuperblog.blogspot.com/)
Spock?s Record Round-Up (http://spocksrecordround-up.blogspot.com/)