Serious distortion from Rega RP1

I had an Rp1, when it was introduced. My reentry after a near 30 hiatus.

Excessive tracking force ?Have you tried backing off the counterweight a bit to hear if it goes away? 

I've re-aligned the stylus/cartridge as it was a little off, I backed off the counterweight a bit, then the tonearm just kept wanting to move away from the center, so I added more weight, now it's slightly less weight than recommended.
I still have the tonearm wanting to move away from the center, but it's less pronounce and it's only when it's high up.

Anyhow, I think it's a little better now, but it still distorts a little especially when there's a lot happening in the song. And the overall fidelity is a little lacking, but I think that's just the nature of the OM5E; stock cartridge, so yeah...

I'm gonna order the Ortofon 2M Red soon & a digital gauge and set it all up to the T then see how I go I guess. Hopefully I get better results, but this is definitely an improvement @tablejockey; so thank you! :D

Maybe the gathering of dust on the stylus.

Have you inspected that the arm has free movement?  not binding from time to time?

@stringreen I'm sorry, could you elaborate?
@raymonda I clean it with the stylus brush every time I am about to play a different record etc.