The problem was all the U.S. discs recycled the same ancient Discovision master with mediocre sound. The common Japanese disc wasn’t much better. The only digital version that seemed to exist was a PAL version in Europe. Someone did eventually find the elusive Japanese Grease LD remaster with digital sound and captured it. Need to bug them about getting a copy. The sync someone else did with my VHS Hi Fi capture turned out great though.

I’d be more than willing to do the captures for you. Analog LD audio is a lot easier for me to deal with actually, as I run it straight into a DVD recorder on the highest quality setting, so the end result is PCM audio.
I have some home repair pending, so I might have to move my gear where it won’t be easy to access until this winter though. Going to try and make space in another room for it if I can.