"Transplanting audio"

[Spektre]

I have a recent VHS capture where the audio of the tape is just terrible. The tape has degraded.

Strangely enough, I have a copy of very good quality audio of the tape from a previous transfer (my capture skills where lacking then and this one has less than stellar video)

Can Vdub "transplant the audio of one capture into the video of another?" That would seem to be "dubbing" at it's purest.

I understand getting the audio in sync will be a chore.

[cholla]

I would give mkvtoolnix a try for this.
It has some Video "timestamp" capabilities & that might be able to sync the video with the audio.

[timtape]

There are exceptions of course but generally soundtracks recorded on different VCR's should stay in sync with each other so long as they recorded identical sources. This is because video has to have pretty tight time base accuracy for the picture. The audio time base benefits from this.

Have you tried substituting the soundtrack into your vision and lining up the start points on the timeline? What happens when you do?