They are on the soundtrack (the title sequence + others) of the 1970 UK movie Permissive (which includes the band Forever More portraying a fictional band). I don't think the music from the movie was released back in the day.
I must be one of the few who listens to the soft-rock follow up To Keep From Crying more often than First Utterance. It's like an occult Fleetwood Mac.
https://www.youtube.com/watch?v=pSctRiv3…
Or the reverse actually.