Use a small soft mallet and steel dolly to tip the last bit of the flange. The tight corner as caused it to bend. The outside edge needs to be shrunk to get it straight.
Just used a shrinker to get it straight at the ends. Can see the cheap soft mallet I used for the tipping and other tools for correcting it until perfectly flat. Bottom edge was tipped and needed very little work afterwards. Only the bottom corners where I couldn't get all the way to the end with the tipping wheel.
I needed to make an extra curved tip to the flange in the middle of the bottom section. Found some scrap under the house and quickly made these T dollies in different diameter rods. One fitted perfectly the curve I needed. This lip turns up to give clearance to the back of the engine cover.
The first part had to stay flat and then the curve was needed. Used a soft mallet as didn't want to stretch it while bending it over. Fitted in quite nice.
Just dropped in place without clamps. Only a slight gap at one end which I corrected later. Was only the bit done by hand and must have missed the mark when bending it with pliers. Cowl sides and top tested to make sure it all goes together. Better than expected but I did remember to take off the material thickness twice when adding on the flange width to the template.