Vintage Marantz 6300 question

Hello everyone,
I just recently acquired a vintage Marantz 6300 turntable. On a scale of 10....it's probably a 6.5 or 7; needs a good tuneup, cleaning....especially the dustcover (scuffed, swirls etc....)

The RCA plug in the back needs a new ground....I'd be interesting in upgrading that cable, if possible.

So....just putting the call out to people who have experience with this turntable (or vintage turntables in general): what I need to think about...how to go about getting it overhauled...and any recommendations about people or companies that do good work.

The turntable works: the platters goes to speed, best I can tell; it comes with an Audio Technica cartridge, although I don't know which one.

Thanks in advance for your advice,
Jeff