Skipper_S
·A 60 year old NOS watch will obviously need to be serviced, so I'm not sure how you listed the watch - that is a key thing to know before I could comment on if they buyer is entitled to anything. If you listed it "as is" then that's that, but if you made claims about the performance or stated that it was ready to wear, then they may have some recourse I guess - no idea how Chrono24 works to be honest.
The part about "upgraded movement parts" is certainly odd, but there's nothing else out of the ordinary in the watchmakers scope of work. It's standard practice to replace the mainspring at every service, and that may be what the upgraded parts refers to - possibly replacing a blued steel spring with a modern white alloy spring. If it was really not used, the watch really shouldn't need any parts other than the new mainspring and possibly some seals.
Cheers, Al
Thanks Archer!
From the photos i shared you see any corrosion?
The watch runs as it should. for sure some seconds off but its also logical.
I will take a screenshot of the advertisement I had so you can see!

