Mark, does it look like little tiny spots as if it was over-spray from paint or something different? I'm not sure what it is. It could be any number of things, release agent that was not sufficiently removed and hardened over time attaching itself to the plastic, mold, actual plastic, etc.
Does it come off easy with your finger nail?
Have you tried running it through the Klaudio?
Three schools of thought on this: My fear is it being in the grooves.
1) If it really sticks and takes a little bit of work to get it off with your fingernail, I'd send it back from wherever you bought it for a better copy.
or if you want to:
2) If it comes off easy with your fingernail, try running it through the KLAudio if you haven't.
3) Failing that, I'd suggest trying an enzymatic cleaner such as Audio Intelligent Vinyl Solutions Formula #15 and then a rinse and run through the KLAudio again. However, if it is not release agent or a protein based contaminant such as mold or house dust or what have you, then I don't know for sure how much that would help. It won't do anything if it's actual plastic or similar.
You could also try a home brew of Distilled water, a few drops of the blue Dawn dish soap and maybe a tablespoon of 91% alcohol, but no more than a tablespoon.
For either of these you will need some brushing action for agitation and you'll want to let the record soak for 2 to 3 minutes. It also may take more than one cleaning.
Just trying to help.
If it were me and I'd bought it new from a shop (internet or otherwise), I'd send it back and get a better copy.
~Eric