Hi John C.
Seems you gave tbonesullivan the right answer. I don't know anything about the subject.
What does it mean? My truss rod is working fine.
My only complaint is the frets. I think they are too low. The guitar was practically unused when I got it.
I see no signs of them being filed down.
There are a couple of things to mention:
In the neck pocket it is written "FOR SHOW" with red crayon.
The neck pickup is off center to the right quite a bit (when the guitar is standing up)
See pictures.
View attachment 33366
View attachment 33367
That truss rod thing occurred in 1980 - it was while Leo was trying to stop dealing with MM and concentrate on G&L. Since yours is a 1977 the truss rod should function properly
Hello! Great guitar!