I'm now doing a search to try to figure a working *and easy 'nuff for dumb person like myself to do* method to recombine one movie put onto 2 DVDs ripped by the ole 321 studios ripper before they got shut down. I've got a big handful of them to put back onto single dvds' if it's possible as I really don't like having to get up and change dvds in the middle of a movie.
in my research came across this ...
don't know if this has info you search for.. but maybe some of the pages of the guide are relavent
http://www.dimadsoft.com/dvdremakepro/ht_merge_full.php