I guess it depends what you are going to do with your rig. If you are going to put on an after market bumper or tow anything you should probably just bite the bullet and get it done with the Trail Tailor C channel kit. Good luck!
Is this going to be a show rig? Going to be auctioned off once completed? If it is a driver again I wouldn’t sweat it. I have bought and sold a good amount of cars over the years and they all arrived on an open trailer without issue. This includes sports cars etc. But if you are losing sleep...
Personally I wouldn’t really worry about it, I towed my rig with my Tundra from Kelly’s to the Front Range of Colorado with zero drama. Kelly’s paint job will hold up to flat bed towing just fine. Brand new cars move around the country on exposed trailers all the time.
+1 for working with Kelly Saad in Flagstaff, AZ. He worked his magic on my 60 and it came out great and now he is working on my 40. I think something to keep in mind is the rust you see is only a fraction of the actual rust buried in your rig. The cost of repairing your rig will be pretty...