Rolex air king

[jubilee5500]

Hi guys I am new to this site, and need some help info I have a rolex air king 5500 registered design 1737541 I think it dates back to 1968. my question is that I have noticed on the gold dials some pitting is this normal? was it a flaw with the gold dial? I took it to a good watch repairer who used to work for rolex and he suggested that moisture might be getting in and he might need to replace the screw where the crown goes in and pressure test it? I don't wear it in the water should there also be a waterproof seal inside?
I'm in Sydney Australia and not sure on how much a proper rolex service would cost or is it worth it thanks guys

[Tools]

Your hands and markers are steel, not gold. Over time they will pit and corrode and they are already 50 years old.

Yes, your crown and stem have O-rings and gaskets to seal and keep moisture out, as well as the case back and the crystal seal. It is a good idea to have these seals changed periodically and the entire movement cleaned and oiled.

[jubilee5500]

hi guys thanks for your last response it was very imformative. since then I found a watchmaker that used to work for rolex he is quite good showed me all his rolex tools etc and has a certificate that he worked for rolex. he replaced the seals in the crown and on the back and the inner seal where the crown screws into he said is fine but the thread is gone that is the barrel the crown sticks out I will be going back to him to get a new barrel he also pressure tested it with water and it passed did the watch back then have glass or plastic mine is plastic not original and there is no seal there I have taken some photos as it now confirms that the watch is 1967 I have heard rumours that rolex will not repair old watches I will aske them for a quote just for fan please if you can please answer alkl my questions as I value your info thanks heaps.