I have a 51 GMC burb. On the 2nd panel of the headliner, the one over the heads of the driver and passenger, are 4 "buttons, perfectly spaced about 14" apart from each other in a perfect square. They are in the exact center of the headliner panel. Has anyone else seen these "buttons" before on an original headliner? It appears that they are there for additional strength and are probably attached to something-I just won't know until the headliner comes down.
