Hi THJD,
I have a number of watches that have the 1010 / 1012 movement ( which is basically a 1020 without the day ).
Accuracy ? they run, I typically wear a watch for about a week, then change it for another. I don't have to re-set them in that period.
I can't tell you if they are extremely accurate or not. ( & to be honest, what if mine aren't accurate & yours is ? ).
I look at then as small machines that are over 30 years old. I wear them because I like the style.
If I was buying a 30 year old car I wouldn't expect performance, fuel economy, gas emmisions etc etc to be as good as they were when the car was new & wouldn't be comparing them with a current car.
How to best take car of "IT" ? I assume you mean the watch in whole.
Well, there are seamasters & seamasters. Some are more dress type watches, some are pure dive watches & some sit in between.
Whichever type it is, I would get the seals checked if you are intending getting the watch wet. I try NOT to get mine wet.
The advantage of buying vintage watches is that they tend not to be as expensive as new watches. so with the money I've "saved" ( that's how I explain it to my wife any way :-) ) I have bought a couple of "cheap" new watches ( eg a Seiko Orange Monster, a Citizen dive watch etc etc ) I wear these when going on a beach holiday ( spending time around sand/salt water, diving ).
I work a lot on cars & my house ( both of which are older than my watches ) I remove my watch when doing these hobbies.
I'd just advise you to use common sense. If I'm entering a "watch hostile enviroment" ( mixing concrete, painting, washing the car, rebuilding the gearbox , whatever..... I just take my watch off & put it down somewhere safe.
I never shower with a watch on.
If you asking how to best take care of the movement. I'd recommend getting the seals checked before you do much with the watch. Some people will say you MUST get the watch serviced every 3-5 years , I don't do this .... I get my watches checked when they drop into the loosing/gaining more than 5 mins a week ( so lets say a minute a day ! )
I'm not going to tell you what you should do. It all depends on you, your finances, if you have a local watchmaker, your priorities.
The bottom line is, wear your watch, enjoy it, use common sense & if it starts with a problem, get it checked out.
I hope this helps
Steve