I posted my bonnet fitting experience several years back, here
You may need to cut and reweld the bottom edges of the wings to achieve a good parallel gap v. the top of the sills, as I did
As to the wings flaring outward at the rear, you will of course need to slacken the bolts on the bonded wing flanges and the tie pieces between the rear of the wings and centre section stiffeners before squeezing the edges inward, then retighten.