Been doing a bit more investigating (when I should be job-and-flat-hunting - curse you, OT!) and uncovered the following:
- Schnitt Berichte has a comparison between the international and US versions - it's in German, but lists some of the extra dialogue sequences not in the R-rated cut.
- There was a comic book adaptation of Moontrap that I've just downloaded from Rapidshare, and includes an interview with Koenig and plenty of photos; would make a great DVD-ROM extra.