Trakhak

I'd definitely ask an experienced frame builder to look at it before putting money, time, and effort into fixing it, if, indeed, it needs fixing. But first, I'd stick a brand new, correctly dished wheel (without a tire mounted) in the frame and check the clearances.

Also, the filing that someone already did might have represented an attempt to fix a (possibly nonexistent) problem and might have thus created a problem.

The initial measurements might have been done incorrectly; in fact, given that you're "new at this" and that titanium frames have to be built to very close tolerances because they're so difficult to cold set, I'd put money on the measurements being off, especially if you and everyone you've shown the frame to have been using the string test or other iffy measuring techniques.

Example: a guy who worked at a shop that I managed (and who had just that week learned about measuring frame alignment) told me that a Marinoni custom-built frame that we'd ordered for a customer was out of alignment. I took his word for it and sent it back to Marinoni. I got a call from Marioni's headquarters a week later saying that (i) the frame measured as perfectly aligned on their alignment table and (ii) they were cutting us off as a Marinoni dealership.