I've seen this before.
Some of my early Music Matter's LP's have it. They deemed it glue from the record sleeve. The marks I have on my lps don't seem to interfere with the sound. Almost like the glue bleached the black from the vinyl slightly. It seems to be on the surface and not deep into the groove...MM's change to different sleeves and the issue is gone. (maybe do a search, a number of folks posted about it 2 yrs or so ago
I'd leave it, you might do more damage than good...
Some of my early Music Matter's LP's have it. They deemed it glue from the record sleeve. The marks I have on my lps don't seem to interfere with the sound. Almost like the glue bleached the black from the vinyl slightly. It seems to be on the surface and not deep into the groove...MM's change to different sleeves and the issue is gone. (maybe do a search, a number of folks posted about it 2 yrs or so ago
I'd leave it, you might do more damage than good...