Concerns purchasing Vintage System?


I'm looking at purchasing a system from a widow that hasn't been played in 20 years. What should I look for? What should I be worried about? I'm a newby to hi fi of the price range.
Audio Research d250
Audio Research d90
Audio Research sp10
Oracle Delphi
McIntosh MR80
Tandberg 3014
La scala
Magnepan MGIII
wsrhue
I am no expert on electronics but I can think of 3 things you should do:
1. Take the grills off of the LaScalas and look for torn or decayed surrounds.
2. Get permission to pop the covers off the electronics and look for bulging or leaking capacitors that will have to be replaced. If there are none and you make a deal, proceed to step 3.
3. Bring the voltage up very gradually on electronics using a variac.
"What should I be worried about?"

Going in, pretty much everything. That stuff is good but old.

You'll have to assess it piece by piece. The actual value could vary widely depending on condition.
thanks, so are the 20 yr old Magnepan planers toast, or just worthless to begin with?
Also, is there any demand for a tape deck anymore? I have a hard time believing what people are asking for Tandbergs on ebay.