Yes on the curve down question. Also, I feel your pain. I did a ton of bending and fussing on my bumper brackets to no avail. Finally gave up and bought a pretty decent pair at a local swapping meet.
Have you tried bolting the bumper and brackets up very loosely and drawing things up with the bolts? Maybe even using longer bolts then swapping out to the correct length. How about bolting one side up and using a long steel rod (or dare I say long screwdriver) through the bolt holes to pry the bumper into alignment with the second bracket?
Best of luck.
