So before DARK ANGEL (David Koepp's rewrite) it was LETHAL CONTACT (Jonathan Tydor's 1984 original script which was quite different), and even before that, an even earlier draft had CAINE & SMITH as a working title (but I believe it was before Tydor submitted it to anyone)...
Matthias Hues has a new book, which is different from his autobiography, it's more about behind the scenes and behind the stunts (including 30 pages on DARK ANGEL / I COME IN PEACE) https://www.amazon.com/dp/B0FJ279CNG