The Ship of Thesus

During this Covid 19 Epidemic I've started to repair some old synths.
With time on ones hands, I can consider the old question of the Ship of Thesus or the Theseus Paradox.
The story goes that after the Greek hero Thesus returned from slaughtering the Minotaur
his ship was left in the harbour as a memorial.
As it's timbers rotted, they were gradually replaced.

Plutarch, wrote about this boat:

"The ship wherein Theseus and the youth of Athens returned had thirty oars, and was preserved by the Athenians down even to the time of Demetrius Phalereus, for they took away the old planks as they decayed, putting in new and stronger timber in their place, insomuch that this ship became a standing example among the philosophers, for the logical question of things that grow; one side holding that the ship remained the same, and the other contending that it was not the same".

So after a few hundred years, when all the old timbers had rotted and been replaced, is the ship the same ship that Thesus once sailed. And if the old rotting timbers were kept safely and then in the future used to make a second boat, then which is the true ship of Thesus ??

So this makes me ask what is the limit one should repair a vintage synth.

 Old Serge Paperface

Do I let nature take its course and let it slowly decay ?
Do I replace some of the components? Do I replace all the old components?
Is the aim to make it sound like it did when new?
Does a synth with vintage components sound the same as the same modern synth?

In answer to the last question I think no.
I have an old ARP 2600 & a TTSH and though they are close , they don't sound identical.

The same is for my Korg MS20s (I have 2 vintage ones), and one modern.
In fact all 3 sound different (though you can hear that they are sonically all MS20s).
And I won't touch the insides of the MS20s as they sound great in their individual ways.

I'm divided about what the correct answer is when repairing historically important synths.
It really depends on how valuable to history, the synth is. 
I think if the synth is unique,  it may be better to simply maintain it until technology is available to restore the original components.

We can always build a modern equivalent that people can use in the meantime.