Ilin

Hello, I'm new to vinyl and just got a rega planar 1, which I love. Most records I got sound amazing. I got a question regarding one particular record from the 50ies. It was listed as in excellent condition and it looks pretty shiny and clean. Yet, perhaps naturally, there are some issues with the sound. I wonder if those can be improved by more substantial cleaning, or since it is a rare item, I should better not touch it too much. The issues are: 1) The sound gently oscillates (like a super-subtle doppler effect). 2) In some louder parts there is a touch of distortion. 3) there is here and there hissing and popping sounds. So far I've only used an AQ brush to clean it. I wonder if any more substantial cleaning would improve the issues I mentioned (particularly the oscillation or distortion) or if they due to age-related deformations of the vinyl or something similar. Many thanks for any advice, Ilin