Lots of other things to do for the last couple of months (and it has been freezing), but last week I built a special frame or jig to hold fenders while working on them. It is built from scrap angle iron, and it matches the shape of the car’s frame rails where the front fenders attach. When a fender is bolted to the jig, it is held in the exact same alignment it will have when installed on the car. The jig is attached to my engine stand, which allows the jig and attached fender to be rotated so the top or bottom can be worked on.
Now it is sitting in my garage with the new repro fender mounted on it, waiting for me to start work.