That is awesome!
I thought I understood how you moved the metal back in position, until I got to the last pic. Is that large contraption surounding the sanding block what you call a target pick in your text? I thought you were using a small hammer pick. Was that a home-made type tool, or are they readily availible? Probably not anymore, as that is becoming a lost art.
My passenger side fender is just about completly rust free, but is crumpled up at the bottom with a long crease in it. I have no idea where to start repairing something like that. Would you use the same technique on a larger crease?
That target pick was made for me as a gift from Cactus John. I think you may be able to get one like it from the specialty cataloges like Eastwood Co.
http://www.eastwood.com/ I have used it to bump out long creases in fenders, along with hammer/dolly set ups. One important tool I didnt mention is the big 2 sided leather bag in the last picture. It has about 25lbs of sand in it and functions as a soft back up for hammer work.
Sometimes with lower fender heel damage the inner brace must be cut out with a thin wheel and a spot weld cutter (or drill bit) in order to get behind it with a dolly and/or hammer. Thin cuts make it easier to weld the piece back after the straightening is finished. A lot can even be done with the cheap Harbor Freight Hammer and Dolly sets.
http://www.harborfreight.com/catalogsearch/result/?category=&q=auto+body Pictures of your fender damage would help determine the repair needed.