Mongo,
Thanks for posting the photo.
Someone posted photos of those buttons/strips in-place, but I cannot find the post.
What are the lengths of the strips, and the hole-to-hole distances?
Would you please take a few closer-up photos of the strips (top and bottom) and some dimensions (and post the thickness of the metal)?
My guess is that the strips have turned-up edges on the long sides?
There is an oldGMCtrucks.com member (in Springfield, MA) with an "all original" New Design Suburban (maybe the head liner panels are original). I'll contact him for info about his headliner.
If you will be fabricating sets of those strips to sell through
Mongo's Garage, please let us know.