I've got the infamous rudder horn hole misalignment. It's not much, but there is a bit of misalignment. What is the acceptable limit of misalignment and how would it be measured?
From what I have heard over the years, it will not affect the flying characteristics if not by a whole lot but it might bug you over the years.
The fix is to weld and redrill.
Why not just have it Tig welded and try again?
That's what I did. He welded it so clean, you couldn't find the original hole. After drilling, I sprayed with matching paint.