I finally saw the film from 1989 on youtube. The romantic sounding Petra's Theme is available on his Music For Film album, but the best cue was the suspense-based music, kind of similar to some of the darker stuff from Two Moon Junction. Not too much score other than this. The soundtrack album features songs only.
Just now I found out that the score track Leave Love Behind is on the b-side of two 7" vinyl singles from the film, Revolution by Mike + The Mechanics and Rude Awakening by Bill Medley.