I started work today by takling the rear curvature of the fairings. By fiddling around a bit I found I could create a tuck in the metal using the fluting pliers, and then drive the tuck flat with a ball=pean hammer. This effectively shrunk the metal as needed. I then found I could use my wood forms, a body hammer and a steel dolly to smooth out the roughened metal and get a nice smooth curve.
The result is shown in Image 1.
Using this technique, I was able to get both flanges to closely match each other, and achiever the shape I wanted. Comparing the fairings against the trim tab control horns suggests I should have pleny of clearance when everything is assembled.
In the Images, I have trimmed the flanges to 5/8 inch, but I have not yet drilled them for mounting.
Total weight of the two fairings and mounting hardware is approx 57 grams. (2 oz)
I am going to use the same screws and nut plates (4 per fairing) that are used to secure the E-616 cover plates to the elevator. This will allow the fairings to removed if needed (eg to inspect the control linkage).