Inheritance piece

[Grizzly45]

Hi all,First newbie post here and glad to be here.After just reading for a few hours I'm a bit more clued in on Rolex than I have ever been.
Anyways, I have a ,going by the serial numbers a 1961[?] GMT master.
It was a wedding present to my mother and lived on his wrist for about 30 odd years going thru all sorts of adventures in Ireland and in the greater world.
When he died it became part of a custody estate story between me and two half brothers I never knew in the States.Short story long one of them got it by default,and kept it for 30 years.I met him recently as we have more time now behind us than in front of us and he gifted it back to me.He basically kept it as a momento and went diving with it ,and consequently had to get the internals repaired in Rolex NY @800 dollars in 2000.After that it has been residing in a safe pretty much since.

So,my questions are the following; From what I can see about these watches its in pretty good shape. Bar an ugly scratch on the pepsi bezel and the odd scuff mark on the glass,what I need is two links for the bracelet to lengthen it again as it is too tight,and the Rolex dealership in Ireland reckons it might be a job to get these. So does anyone ,if need be have two links for the bracelet?

I cant find any info on how to set this for dual time on the net.Plenty of info on the GMT 2 but zip on the vintage model?There is no facility to move the hour hand or the GMT hand when you pull out the crown.Its a two pull before the hour minute hand date starts moving.So how is this done on the vintage models??Or is there any downloadable instructions on the site here?

Also,the dealership suggested getting it serviced.Whats the average price and SOP for such a service?Does that re certify it as a chronometer?
Thanking in advance for the advice info from a Rolex newbie
Grizz.