When I was at the Mopar Nats in 2007 I asked AMD,(Auto Metal Direct), that very same question as 340 brought up. Was the re-popped sheet metal as thick as the metal in OEM 1970-74 Chrysler cars? He and at least 2 other reps said No way!
I would try and find used. A great place to find most of all the 'used' MoPar sheetmetal dealers as well as the complete aftermarket spectrum, and private persons selling their parts can be found in this handy publication that fortunately ships worldwide.
www.moparcollectorsguide.com I have used them successfully in the past