Request for help: 1570 serviced 20+ years ago

[MGMCC]

Hello all,
I would appreciate some guidance and advice about a 1570 movement watch that I’m looking to buy. The watch was serviced around 20 years ago, it was a full movement service by Rolex, I’ve seen the receipt that matches the watch’s serial number. The seller is representing that the watch was unworn since the service, and the external appearance seems to bear that out since some case parts were replaced by Rolex.
I’ve asked the seller for a Timegrapher or other measurement of the movement’s current performance, the response that I got back was that the watch “is running perfectly.”
Given the amount of time since the Rolex service, would it be expected that the lubricants for the movement would still be okay if the watch was in fact unused since the service? Also, I’m located in Hawaii and don’t have easy access to a Rolex trained (or other) watchmaker to check the watch’s movement - should I just assume that it will need a service because of the amount of time since the last service, even if it was in storage?
Thanks in advance for any help and guidance.
Mark