Vintage Rolex Datejust 1978

[retinamdphd]

I was recently gifted this Vintage Rolex Datejust from my father-in-law. I'm sorry about the poor quality, it was taken with my iPhone. It was apparently rolling around in the bottom of his desk for the past 30 years. It has never been serviced, but amazingly, I wound it up, and it basically keeps time like my new modern Rolex Explorer 1 (ref. 214270). I'd love this forum's help and recommendations on what reference this datejust is, what the movement it likely contains (3035), is the bezel white gold or steel? How should I get it serviced so that it does not decrease in value? What kind of service would you recommend? Should I get the case polished? Should I change the dial / hands? Should I change the acrylic crystal? Or should I just get the internals and seals freshened up, and leave it as is? What would you do if you came across your father-in-law's old datejust that he hasn't worn for 30 years. Thanks for your help and suggestions!

I've posted in some other forums, and they recommend getting the acrylic crystal replaced, do NOT polish the case, to possibly get the dial and hands replaced, and maybe replace the jubilee with a period correct oyster bracelet. I'm not even sure where to begin. I have to say it has a wonderful patina, and it looks great on my wrist. I have a few other modern watches, but this vintage watch definitely has some style.