C body replacement quarter panel availability

Has anyone ever found replacement/after market quarter panels for 70 C-body Chryslers? I have a very nice looking 300 Hurst, but I am a bit suspicious of what might be under my shiny paint on my quarter panels. If/when something underneath begins to fail, I'd like to have replacement sheet metal at the ready and not have to rely on total fabrication of the right shapes of metal to do the repair before repainting.
Author: noah300g