If the flare can be cut out and replaced where is the best location to put the joint? I want this repair to be invisible on the inside when done. I would like to purchase the quarter-panels and tubs ...

Q. I am working on a 1970 Ford Mustang Mach 1 and have a question regarding the flares on the rear quarters. There is rust in the flare section of both quarters, as well in a small portion of the tubs ...