Picked up a 94 fender jazz bass (MIM).

It spent a long time in a basement and has some surface rust on the bridge and such but the real issue is the tone pot. All the pots were very scratchy so I've been working at cleaning them - better, but not great. Got it for $50...sounds great and plays nice, other than the pots.

I see lot so fender jazz 'wiring kits' on ebay...some with a large orange cap and some without. For $20-25 it's almost a no-brainer to change the pots/wiring.

So, what I am looking for, or avoiding, and why? What's the diff?

It has a one piece pick guard. Most I see are two piece ... are all pickguards (2 piece) the same fit-wise or do I need to find something specific to a mid 90s MIM?

the one tuner key is loose and rattles (where the blade attaches to the shaft). Looking about the net at tuners I"m a bit lost...seems there are 'vintage' and not tuners and they're different. How? And are P-bass and J-bass tuners the same? (I assume...)
I see a ton of choices...std, deluxe, american, vintage..what fits (or not) and what is the 'best' choice - I see some 'fender squire jbass" for $20 for set of 4 .. most are $60-70 and some a bit more. I Like $20 if they work as well as the factory, if i have to spend $60-80 then I want 'the best' of what's out there.

Painting..it's a black bass and my son (it's primarily his bass) and he's expressed an interest in a blue/teal color of some kind. I've painted a car or two in my life so figure it's not outside my skill/tool set...what paint is normally used? Automotive or ??
For electric, I like a lot of coats of lacquer(sand, coat, sand, coat and so on). If you want a satin natural, true oil would work great after the blue stain.
My son wants this crazy blue marble finish. Crazy kids.
96 MIJ Jackson
Charvel DC 1 FR
PRS SE Custom 24
Yamaha FG730S
DIY acoustic
DIY mockingbird
Peavey classic 50 2x12
Krylon Acrylic Lacquer (not Enamel) in spraycan is the easiest, dries fast, etc.:

As far as tuners, I'd just go eBay and look for the specific MIM JBass tuners for your model (Standard?). BTW, what amp/cab/combo is he using?

Good Luck!