To the best of my knowledge, "Love's So Easy" was never released anywhere, and there was no soundtrack issued for the film. The title song by Don Dunn that plays over the end credits, however, was issued as the b-side of a promotional single with the radio spots for the film. It is entirely
possible
that there's another variation of the radio spots 45, but I wouldn't think it very probable that it would include Laurie's 1930s-ish tune, which wasn't exactly radio friendly in 1977 (unlike Dunn's schlocky pop song). And since director Curtis Harrington's original cut of "Ruby" (prior to massive tinkering by the producer) has been lost, I wouldn't expect that the music has survived either. But I've learned never to say never if someone can prove me wrong, I highly encourage them to!
http://carriefansite.blogspot.com/