Hi Rob.
I was in a similar situation almost two years ago. Here is what I did.
I used MPEG Streamclip to demultiplex the *.VOB files which contain the *.M2V compressed video file and either the *.AC3 compressed or *.AIFF uncompressed audio file.
Once this is done, you can readily import the assets into a new DVDSP project, and re-create your menu. MPEG Streamclip seems to be extremely good about not modifying the assets as they are demultiplexed.
Here is the URL for Mac:
[
www.squared5.com]
I hope this information helps.
Take care.
-DH