Looking for parts or ideas
 

So I inherited a 1989 grand marquis from my grandfather and I've been trying to restore it. I am looking for fiberglass piece that goes under the vinyl on the back half of the roof but have had no luck finding a new one or any donors in the junk yard. It's like these cars are almost non existent. I'm in northern AZ but have tried every wrecking yard from here to Phoenix with no luck. Unfortunately I've got the rear fiberglass valance around the back window so as far as I know I can't just delete the vinyl top without it looking like crap or doing a lot of body work. Any suggestions would be awesome. Maybe was thinking having someone make a fiberglass shell custom but feel like that's gonna be expensive.
https://cimg1.ibsrv.net/gimg/www.mer...e9cc62400f.jpg