I have a 1979 Strat that i've been using for a little over a year. It's my first electric and I haven't done much with it besides change strings every now and then. It's usually kept in the case when it's not played. (sometimes closed, sometimes case door is open)
It came with some dings and chips on the tail but overall the paint is great and there is not much checking and just a few hairline marks on it. (It's defiantly been gigged/road worn) I'm almost positive it was kept in storage in a garage before I bought it because the guitar/case had a gasoline aroma to them. (mostly gone now) I took off the pickguard and checked inside and the wood looks ok. No mold or anything.
The fretboard does have some random small chips where the lacquer has come off, mostly on the sides of the neck, resulting in some slight darkening of the wood at those spots. (the chips on some of the frets isn't discolored, just noticeable at certain angles that the lacquer is gone)

Anywho, I get some fret buzzing here and there that restringing and adjusting the intonation hasn't been able to clear up. (I know, I know. It needs a new tune up) I had a luthier check it out and only thing off he said was that some of the fret dividers need to get hammered back down. (had a triangle shaped tool that could see if the frets were raised out too high.
Also due to it's age, there is some rusting on the bridge/saddle and intonation screws. (plus 2 of the 4 neck plate screws on the back are rusty) I'm not sure if this would affect the vintage/collector value to have some of the hardware replaced because of rust or not. (tuning pegs aren't too bad, just need to be buffed up or something)
What would you recommend for standard maintenance of a guitar of this type and to keep it from deteriorating more? Any thoughts on replacing metal parts/affecting value? Please don't flame. I'm a newb player, but i've always wanted this era guitar and had the chance to get it, so I did.

There are no fine tuners, just two screws to raise the bridge on the High E and Low E sides. I am getting insane amounts of buzz, and when I can manage to get the buzz to go away *even a little*, the intonation is terrible. The neck has just been shimmed, and a new zero fret has been installed. What do I do? I love this guitar, and I'm desperate.