Thanks Dave,

This would make sense - and would also explain why no matter what I tried to do, I couldn't get the wheel to center. I can definitely do the seat stays first, I just wanted to make sure I didn't need to totally remove one of the chain stays before I brazed in the seat stays as that seemed like it would complicate things further.

So just so I'm clear - you're suggesting I take a half round file or something of that nature and on the side that's further away from the wheel right now (non-drive side) make some file strokes on the back end of the dropout one or two at a time and test between each for alignment.