Cleaning vintage amps

This is along the lines of the thread about cleaning the RCA jacks...I have also purchased some vintage gear and it is in need of cleaning.

One unit has tons of dust and dirt built up inside and even a little rust on the outside heat sink area.

Can some of you comment on how you clean your gear? Is there anything I shouldn't clean, or touch? Can I do damage to any parts of the amp by cleaning it?
Thaks folks.
Compressor with thin long rod will blow of most of the thick loose deposits. If one not available, try spray-can dust blower. Rusted components should be replaced, and heat sink easily sanded.
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Pure alcohol (isopropyl alcohol) can remove the decals (logos) and lettering on the chassis.

Better to use Contact Cleaner which is designed for this purpose. It's available from most electrical supply stores.
let's not forget the good ole' Electrowash trichlor spray cleaning solvent. Ensure that whatever you use won't attack plastics.