WRT He absolutly does not want to cut the fender wells

Is his concern originality, or just structure and air management?
If he just wants the shock tower stiffness retained, he can reverse-box the tower where the header bend will contact. Many cooking utensils, industrial containers, fender scrap pieces, etc. have useful shapes like shallow bowls so you don't have to fabricate a 3-dimensional patch.
It doesn't absolutely need to be welded (but I would if you can), 1" overlapping seams + double row of pop rivets is enough.