Re-reading this thread, and trying to type with a fooked up middle finger full of stitches, but, this is not your average hobbyist build! Pat, what is your background and job/experience? I got to say, there's a ton of money tied up in this car, I'd say a good 50k so far! One thing I think you should have done is a complete media blast; not soda nor sand. Reason is of course the metal gets clean, but it 'punches' at the metal finding weak areas that would never be discovered. Your repairs by your rear window are great, but, I promise you that there likely is more weak and compromised metal back there and other areas in same condition. I say this with about 100 MOPARS I've Media Blasted, and about a dozen GenII Chargers.
The Alterkation; the Inner Fender bracing; Im curious if removing the complete factory system of sending energy through the Torsion Bars to the center section of the car compromises too much of this natural balance -- and can the inner bracing you added replicate this and does this new system transmit to much energy -- and into the upper cowel area, meaning can this area handle it, an area clearly with little to no structural designed systems to handle this new and incoming energy from the road?
Again, this is no average Joe Blow hobbyist build!