please help me identify my grandfather's (1960?) Rolex!

[grandfatherswatch]

Hello Rolex Forums! I was referred to you all after posting a thread on reddit's /r/watches, and that thread not turning up any info, and then another post on Watchuseek turned up similarly empty – I'm hoping that you all might know more!

I received the Rolex described here as a Christmas gift from my father, who found it among my [deceased] grandfather’s possessions while helping my grandmother move into assisted living. Unfortunately, with my grandfather having passed away and my grandmother’s mental health tragically degraded, I don’t think there’s any firsthand source of information beyond what I describe below – but anything that your expertise can reveal would be very interesting to me! (I certainly don't want to sell it, but I would like to learn more about it and care for it appropriately – and hopefully wear it regularly!)

Photos of front and back. (I neither know how to, nor would I feel even remotely comfortable attempting to, remove the back to photograph the movement.)

The text on the front reads:

Rolex Oyster Perpetual
•
Officially Certified Chronometer

It’s difficult to read the inscription on the back – I couldn’t photograph it legibly – but the watch was given to my grandfather by my grandmother, evidently for their wedding anniversary in 1960 (inference from my father), so that was, I assume, the year it was purchased. Judging by the amount of scuffing – enough to obscure the inscription but not to meaningfully obscure the movement – it was his daily-wear watch for a long time.

As well, while the watch is still functional (term? the hands still move), it is not currently useful, as it seems to be slow by about 5-10 minutes/hour – is it possible to restore such a watch to fully operational condition? If so, how best to do that (how much will that cost?), and how best to preserve it in such a state, especially if I would like to wear it regularly?

Happy to supply more information to the best of my ability; thank you for any input!