Teach me about cartridge 'retipping'

Thought I would throw this out there for comment by long time vinyl aficionados...

We all have cartridges we love, some are pricey treasures... but they wear out eventually even with much care and diligence in use.

There are still some good folks with excellent reputations doing retip services of various makes - Peter at SS, Andy Kim in WA, Steve Leung in NJ etc etc... not to mention some of the manufacturers of course, who still do them. It would seem to me these old craftsmen may or may not be passing along these valuable skills to younger apprentices.

I have bought a couple Grace F9 retips from Peter Ledermann - they work wonderfully. No longer having a fresh factory F9L I will never know whether they sound different.  But they sound great.

Curious to hear comments about how these retips are done, and whether they can reliably reproduce the original sound signature of the cartridge. I wonder, for instance, about how the cantilever is removed and reinstalled, relative to the suspension of the original cartridge, etc etc.  Is the suspension replaced?  What is a suspension comprised of, for example, in a typical higher end MC cart like a Dynavector a Lyra a VDH...

Of course, as time passes, the original cartridges age and I can imagine suspensions in them eventually get compromised as well...