Sure, reauthor in DVDShrink and compile both titlesets. (No Menus!). Save it, no compression. Then open the VIDEO_TS in DVDRebuilder and re-encode at Half D1. Options -> AVS Options -> Advanced (Expert) Options -> Resize to Half D1 -> Apply to All. That's assuming both discs combined are over 7 Gigs (subjective opinion here), if not you could compress it normally in Shrink or Rebuilder. Doing it at half D1 ensures there's enough bitrate, rez willl be slightly softer (about like an SVCD) but no compression artifacts. Half D1 (352x480/576) is DVD Compliant.