Hi Oliver,
I dont´t think, that your fenders a beyond repair.
Your fender shows the typical damages and repair welting on a former Greek Army Vehicle.
Cut out the bends and dents step by step and weld in new matching sheet metal patches . It will need time, but it is it worth to keep original material. Otherwise when you take a repro fender, you will have some work ( sometimes hard work) to get it in your Jeep.
The fenders of my Ambulance where very similar to yours.
The rest of your Jeep´s sheet metal certainly will held some welding work for you too. So the best way is to "learn to talk with sheet metal".
Here are my fender when I start restoring.
some damage from an accident.
after stripping the filler.
After welding ( the right one) both fenders looking equal.
Welded, sand blasted and primed.
Only a small layer of filler was needed.
Berlin Brigade style turn signals installed.
Frank