Here are the before and after pictures. I had to file out about 1/8 of an inch. I don't have a before picture of the left elevator.
Dominik told me he had cracks on his elevator horns, and suggested I check mine. Sure enough, I had cracks too. I took the elevators to an aviation welding shop, and he said he could fix them, but it would be best to just file off the cracked part. I called Van's, and they said the same thing, so that's what I did.
Here are the before and after pictures. I had to file out about 1/8 of an inch. I don't have a before picture of the left elevator.