OK. Not much luck when I posed this question in the GT40 forum...
...so I'll try it here.
I have 1 of 2 projects that I would like to pattern seats similar to that you find in the GT40's: Leather/vinyl with the aluminum/brass/stainless inserts. I'm quite sure that such material won't be found on the shelf and will have to be fabricated using the inserts. The question is...where?