I have totally rebuilt the crossovers in my M60's, VP150, & QS8's
I constructed them using the factory inductors, Mills resistors, & Sonic Caps from Jeff @ Sonic Craft. I used like for like values for the resistors & caps. I built new boards using point to point wiring.
I also did some internal damping work and replaced all internal wiring with Teflon coated 14g Tef-Flex AG from North Creek Music.
The result was nothing short of stunning. Sound is very fluid, extremely detailed, huge sound stage, speakers have actually disappeared.
Any & all problems with top end ear fatigue, edginess, or harshness are totally gone! Mids and highs are now simply beautiful.