When to get your amp up graded caps ???

I read some where that the caps in an amp should be replaced after ten years and the amp set to factory specs.
But I have owned some that were 20 to 30 years old and the amp seemed to play fine. However not knowing what the particular amp sounded like new I couldn't say for sure if needed or not but it certainly makes sense to replace them with that vintage if:

1. You plan on keeping it

2. Your not satisfied with it's sound and feel it could be better.

3. Your willing to and can afford the investment compared to selling it and adding the cost of upgrading towards something more current.

Cheers

Why not give Audio Classics a call to see what was done to the amp?

I have no idea how it sounded when it was new, that would have been nice... but have enjoyed it since it's been in my system... contacting Audio Classics would be a good idea...I guess when you become audio obsessed we worry about too many things, but you want the best you can get, with what you got...
Thanks...