Another Tool said: Nah, it's a strip of plastic that runs around the fretboard. Les paul's normally have bound headstock fretboard and body, same thing, you've seen it.
That's what I meant, I just didn't describe it well.
I Googled a pic of a 65 Jazzmaster neck and saw the plastic. I used to own a steel-string acoustic that had it.
And yaeh, I've seen it on a thousand Les Paul's
Thanks for the info, lads 😀