frequency of servicing Rolex?

[kinnick24]

Is there a "rule of thumb" on how often a Datejust model should be serviced?

Picked up a 1965 datejust 14k & stainless on eBay recently and don't know the service history. Showed it to a jeweler who said that I should have it serviced/overhauled. Bottom line, watch has one medium scratch on the crystal, but presentation is good and it keeps good time. Was also recommended to replace the watch hands and go with a leather band. Jubilee 14k and stainless band is old, but looks and feels good. Is there any downside to wearing the band until it finally wears out?

This is my first Rolex is 20 years. Back in the late 1980's/early 1990's I had a GMT Master and a stainless datejust.

Thank you!