I own the above mentioned guitar and i think i need to replace the nut. its from the 79-80's era and ive got some fret buzz on the first few frets. ive made a lot f different adjustments and the first few still buzz, but not so much the open notes.

I was wondering how to figure out what nut to get. What size, the notching, the material etc...

Any other things you guys think would be causing just the first 4 frets to buzz? the action is pretty medium, 4/64" on the low E string at the 12th fret. truss rod mostly straight with a slight backbow, very slight.
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