It's a little bit of a mess. Plumeri did additional music and the score is supposed to be by Paul Di Franco, with leftover scoring from a rejected score by Pete Haycock & Derek Holt.
Heycock is still credited with guitar solos, Plumeri is not only credited with orchestration but also in the films' trailer that still lists Heycock & Holt as the composers, so apparently he worked on both scores.
