Change the outputs in my Crown D60?

[oldglide]

My old reliable Crown D60 is starting to show it's age. Has worked great for over 30 years in many roles, headphone amp, main amp and part of a bi-amp system, a thread I want to pursue later, but I think it's getting old. While doing my somewhat regular bias check I noticed that the voltage drops are all over the place. All within in spec, sort of, but being the anal retentive guy that I am they all should be closer matching. I also noticed the the heat sink compound has turned to cement, LOL. I'm thinking of replacing the aging 2N3055 with new or an acceptable substitute, comments? Also, does anyone have any experience with the silicon insulators that can be used in lieu of the mica ones and the goop?

[nigelwright7557]

Silicon insulators work fine, I have used them many times.

I would stick with the 2n3055 but replace the heat sink compound.
Using newer faster transistors might result in some instability.

I used to use a Maplin 225WRMS 2n3055/MJ2955 amplifier for a disco and it gave many years of good service.

The only thing that might be a concern is the electrolytic capacitors as these tend to age first.