The radiator support top and bottom cross bridge rails are the most difficult, but once they would be made, I'm not comfortable with just bolting them on as cross hinge in place of welding. They are structural to the chassis strength contrary to the belief of the K-member taking all the blame.
The stamped side walls are easier, but still time consuming.
There's a lightweight A-990 repro version on E-vague for only $$$$$$800 LOL.
If only aluminum/Titanium could weld to other steel structures. That being said, there is belief that bolting something to another is actually stronger than welding (Bridges, elevated Subway tracks etc) But I still want a weld. So on that note, no, I will not recreate the whole thing, but there will be a small portion of the frame rail longitude made out of aluminum that will slip into the original and blind bolt through. Everything else will reinstall and look stock and weigh less.
When Skicker saw the twinkle in my eyes at Carlisle when I was looking this very same cross member part at his booth, he pretty much said, I know you are up to no good. We laughed our a&$es off. By the way, at his booth up against the fence at gate #7, he has an abundance of small and large parts along with the knowledge to help almost anybody. He's a great source of fact and chat.