After about 3 hours of research, I think I’ve found it: the second disc on https://store.shopping.yahoo.co.jp/dss/wpcs-4621.html have the same pieces with identical or near identical times. it is also the only thing I’ve found that is remotely a good enough match.
This still﹡might* be a standalone release, the original freedb (yes, I know) suggests that, there is no “disc 2” anywhere, which even in freedb is common (and especially by Japanese users, I would think?)
On the other hand, for having a name like “ピアノ名曲集” (Piano masterpieces collection) the omission of Suite bergamasque seems strange. (it is included on the 1st disc of https://www.amazon.co.jp/dp/B00005HH9B)
So therefore I’m going to just convert it to the disc 2 of this release, import the first disc and call it a day.
Should anyone with the original disc id actually come forward again, they can damn well create a new release and move the appropriate disc id there! :p. anyway the recordings should be the same.
Unless anyone disagrees?