Aged components / service!?

I tried to get an insight in what is considered aged components in a pre amp. I look at a pre which is between 10-15 years old. Personally i kind of feel this is close to a no go. I get conflicting information with regards to service and age.
Do we have any members here who could actually teach me something regarding components and age?

Almost none of my kit is UNDER ten years old.

My Audio Research SP10 is iconic and 1983.  Only re-valved.

My Krell KRS200 References are from 1985.  Fully rebuilt once, mostly just new capacitors.

Both coming for 40 years old.

I am still getting great sound from both.  Truthfully there has not been much advance in amplifier design since the 1980s, whatever today's designers try to tell you.  This is mature tech.

And they've long since paid off what I laid down for them.  Indeed, they're now worth more than I paid.  So, free high-end listening from top-ranking vintage amps by top designers who were honest then.
Don't listen to posts saying 'buy young'.

My Simon Yorke S10 with Aeroarm is 2008 and still state of the art.  It will run forever.  I just add a few drops of oil to the bearing once a year.  Simon's previous S7 was Fremer's reference for 8 years.  My Aeroarm is one of only five customer pieces and a huge improvement on the pivoted S7 arm Fremer had - that he changed for a Graham, I recall.

Don't buy the current spew of blingy, trophy chrome-plated turntables.  Buy properly thought out engineering at a tenth of the price.  Nothing wrong with vintage Garrards, Thorens etc either.

And @rird...   If you ask a dealer about old equipment, what's he going to make out of it ??   He wants to sell you new stuff, at the biggest bucks he can persuade you to shell out.
I had issues with an older PMC active speaker, my ex Wadia 381 (repaired), my Krell KPS 25sc (repair and expensive as hell).
So i have had my share of experiences. That Wadia cost about 1200 usd to repair and Krell device about 3000 usd.
I have had many pieces of used high end gear over the last 50 years. The only one needing repair was my tubed Sonic Frontier CD Player that would have the CD transport go out every few years (I bought that new). That is it. All others, some 30 years old by the time I traded them in had a problem.
+1 for Dynaco and Hafler. David was quite the amp engineer. My 51 year old Hafler DH-220 sounds sounds so right after Musical Concepts brought it up to modern specs on 12/31/1989, Then three months ago it was literally rebuilt, meaning very little original remained. I was nervous when it was being rebuilt for the second time.... wondering if it will still sound original (as close to tubes as you can get with MOSFETS.) Break in day.... OMG! It's ruined! A month later it is like it used to be but deeper bass, more guts, sweeter sounding mids and hi's.....