Copying the files straight off the disc should be all right. DVD-RAM was intended as an erasable, recordable version of DVD-ROM, so there shouldn't be any copy protection.
Years ago, it was possible to open the DVD_RTAV in the (now obsolete)
TMPGEnc DVD Author and make a DVD. I don't know if its successor,
TMPGEnc Authoring Works has retained this functionality, but it's trialware, so you could have a go.
Alternatively, try renaming the VR_MOVIE.VRO to VR_MOVIE.MPG. Can you open the resulting file in
DGIndex and demux/index it? Also, try running MediaInfo on the file to get some information about it.
Renaming the .VRO to .MPG is not absolutely ideal because the content might be fragmented, but the choices are likely to be limited. I don't have a DVD-RAM to test, so I don't know what software supports it these days. It's been ages since I've seen one.