Hi John and welcome to Stovebolt.
IMO, When you get right down to it, there's really not that much different between the Art Deco suspension and the Advance Design suspension to make it worth the trouble of putting Art Deco sheet metal on the AD frame -- you'd be putting a lot of effort, time and money into it and getting marginal/no improvements.
We have a lot of 'Bolters who have made some impressive rides out of Art Deco trucks -- TrknGMC comes to mind. You might talk to him and the others about just getting an Art Deco truck and making a few mods to it to do what you want to do. It would probably be simpler. Keep the engine, though
What a lot of folks do (me included) is once you get the truck you want, just get it driveable. Just enjoy it for starters and get to know it. THEN start doing incremental improvements. All of these trucks seem to have a good starting point for reasonable drive ability upgrades -- even with a straight axle.
Just a thought, anyway.
John
