Pickup is PWY1003, replaced with PWY1010. Refer to Pioneer parts website for cross reference. Please - NO WATER CLEANING on Pioneer pickup lenses. The original glue used is hygroscopic, and additional water exposure may lead to pick-up lens loosening in it's socket. I always fortify the bond with epoxy when working on those players.
I do disassemble pick-ups for cleaning and repairs as needed - I do remove the lens if I need to clean inner lens surface. Laser diode and the diffraction prism and optics are accessible ,too, but would not advise to do it for a beginner. Use 99.9 isopropyl or 96 ethanol for cleaning.
Doctor has it laid out it all good, the scope is a must to proceed with your problem. The issue is that decent analog scope is much more expensive than PD-4100.
Scratchy noise means proper tracking can not be achieved - sadly, that means the scope is needed.