Lukas, I recall EARTH II quite well, but had forgotten that Gary L.ockwood was in it, remembering it as starring Anthony Franciosa.
I had recorded the main title to my trusty Sony Superscope reel-to-reel recorder back then and was somewhat miffed that the mostly in the clear main title was soiled by Franciosa's line, "Earth II", when the station comes into view.
The end title music is pretty much the same as the music as Franciosa's ship first approaches Earth II.
I remember this show and someone pointing out that it didn't work because it was not an "office" show. Star Trek is the ultimate sci-fi "office" show -- the Enterprise is the office, and travels to where the story is. Earth 2, the people were wandering around without roots. Sci-fi is apparently really hard without the office. No kidding!
Logan's Run and Planet of the Apes (TV) are other examples for that, I think!
And, after all these years, an official release of the score would still be great!