Transcribing lacquer masters part deux

I’d asked for advice from the community here about a year ago on this and wanted to let everyone know where things stand and ask a bit of advice.

After several months of delay, I finally received the two master discs from the original musicians to transcribe. On opening the box, I was worried: The surface of both master discs was dirty, clearly abraded in some areas and the lacquer itself appeared to be cracking. They had obviously not been well cared-for since they were produced in 1981. Fortunately, I was also sent a copy of the LP made from them at the time for reference.

So, I use the Library of Congress go-to Disc Doctor’s Miracle Cleaner for lacquer and obtained... Not much improvement. Maybe they were cleaner, but they sure still weren’t in very good condition.

Started with the vinyl LP to get an idea of the material I was dealing with, and the disc was essentially new. Fidelity wasn’t the greatest, but it was a low-budget pressing made for a regional wedding band so that was not a surprise. Even so, very quiet with adequate frequency response and dynamic range. Successfully transcribed to Red Book without issue.

Not expecting much of the masters, I got started on them. Good thing I wasn’t sanguine: Pervasive and substantial surface noise. The fidelity and dynamic range were substantially better than the LP, but the surface noise remained obnoxiously audible across all 10 tracks. I completed the transcription anyway, so the noise is captured in all its 24 bit 192 kHz glory.

I know that lacquers are brittle, not intended for playback and can’t really be rescued once they start to degrade. And these two were done to a budget to begin with. Even so, does anyone know of a lacquer cleaner or preservative that might drop the noise floor? I’d like to provide a better result than the Disc Doctor fluid delivered if possible.

Thanks in advance for your input!