Mark,
Can't you find an old malibu or elky around, they are the same from 1978 to 1988 and they are plastic from the factory, i still have the originals in both my 80 Malibu and my 79 Elky. I only cut a small section out of the left front for the front mounted fuel cell.
I think the Olds and Buicks G bodys have the same panels in them.
Zip.