You might try contacting Paul at GMC Pauls...
http://gmcpauls.com/ He doesn't specifically deal with suburbans or panels but I believe he knows Jim Carter fairly well and may be able to advise if the panels are good enough to work with. Paul no longer has a contact phone number so use the email and see what you get back. NOTHING I've seen yet in the repro world fits exactly but a good shape to begin with makes a huge difference over hand fabricating from a flat sheet.
