Fender nitro or poly finish on early 70's fender basses

[spectroscopia]

Hello fellow fender experts.

I have a question for you.

I have a 69 and a 72 fender precision bass, I have heard that the finish after 68 was poly. Is that 100% true? As the lacquer on 2 of my basses seem to be original and very thin. I thought that from 74 fender started to use he thick poly finishes on fenders. Correct me if I am wrong. Or maybe from 68-74 fender used some super thin poly finish?

 

[Lownote38]

At some point in '68 they went to poly except for the front of the head stock which remained nitro until some time in '73 - '74 (I haven early '68 that's still nitro, but it's more like a '67 than a '68 due to the logo they used). I think the poly did get thicker when they hit the mid 70's. Much thicker!