Old records.

@puptent It's amazing how many of us do use alcohol in some form (isopropanol or ethanol) in our cleaning solutions and seem to get away with it. The 'ripples in a sandbar' appearance is something I associate with the discoloration caused by PVC outer sleeves.

Many of us were not near as good with record hygiene back in the old days. Styluses were not as well polished and were of types that caused more wear. They were also in many instances larger then many modern styluses.

Before giving up on 3000 records I would suggest cleaning a few, preferably with a vacuum cleaning machine. The Ortofon Replicant 100, Gyger S and Soundsmith OCL styluses have much longer contact areas than old styluses and can bridge over worn areas. They also tend to be quieter. You might want to consider a cartridge containing one of the above styluses.

Unfortunately, many records are going to be suboptimal. My oldest records from the 60s and early 70s are pretty rough. Some of them came from the factory that way. I only kept the ones that I could not replace or had an emotional connection. to 

I think the consensus here is that records are maddeningly inconsistent.  

It seems to me that it's something wrong with your system, not your older records.

My record collection is predominately 80's music and ones pressed in 80s..90s sound more superior ones pressed recently or re-pressed. I can't even think of comparing modern day releases of Zeppelin vs. original Ludwig releases

I am happy that this matter about the material pressing of vinyl was touched upon  here instead of  usual the alleged superiority of vinyl which for me in the actual digital state of the technology is only a matter of the cost/design /level of the concerned technology when compared to each other  ...

I am happy that this was discussed openly because it was the reason i quit vinyl buying spree BEFORE digital enter the scene ...

As i said when digital came the sound was horrible because it takes at least two decades before this technology was mature enough ...

As an important observation this does not means that all vinyl pressings were bad , at this times i owned a hundred vinyls it is not a big sample enough to gave the right information .... Then i may had been unlucky with my choices and it was half classical and half pop or folk ... This post of mine relate only a limited experience not the truth of the vinyl market at the times...

I remember well why i listened mostly only Bach because i was disgusted with vinyl buyings and not picking the best interpretation first but the more solid and well pressed one .,.. The other reason was my unsatisfaction with the sound quality of my audio system , even with a Sugden Amplifier and Tannoy dual gold concentric ... I did not know anything about what i learned in Acoustics and embeddingas controls in the last 10 years..😊

Then being ignorant my only way to improve the sound was buying costlier component ... But how to improve Tannoy dual concentric and Sugden ampliofier when you are relatively poor ? I did not upgraded ever from Tannoy or any other component i quit buying vinyl till digital ... Upgrading i know it now would had been a disaster because of my ignorance in acoustics and embeddings ...