I got through the Japanese track last night, and working on the original mono tonight. The 1994 disc has some speckling issues on side two, but not enough to affect the soundtrack. If I do detect any static noise issues, I'll just use side two of the Criterion, as it's well past Castle Anthrax.
As an aside, I can't believe how bad the old '83 LD looks. (Not just the laser rot.) The print was either badly color timed, or faded in some way. The greens are just gone. The peasant scene is a field of gray grass, and the Green Knight is also devoid of color. Every video release until the early 90's probably looked like this.
Wish I still had a CED player to justify getting RCA's letterboxed version.