I had the entire car stripped with no surprises and the last panel was the top of the hood. I immediately discovered that the first layer of hard, black primer was noticeably thicker than anywhere else on the car. Then I discovered why.
Many areas on the surface of the hood panel were peppered with hundreds of small "dimples". Several months ago during my experiments with vacuum forming ABS I overheated several sheets of the plastic and the result looked identical to what I'm seeing on the hood. Whatever it is, I'm certain it was there when it left the factory. There is no evidence anywhere on the car of any previous body work.
Has anyone ever seen this before? I guess I'll just do what GM did and lay on a little extra primer. I don't know if this is something unusual or if it is typical of GM quality back in the Roger Smith days.
The dimples are mostly concentrated in the circled areas.
The next 2 pics are zoomed in on the area in the large red circle on the left in the above pic
The next 2 pics are from the nose area of the hood.