The visual might point to something off, but not What or Why. Yank the fork, and the race and get it in a reliable fork jig, let that advise as to how and why it might be off. I would not attack a fork with a file prior to doing the double check. Measurement can also be done on a effectively equipped alignment table.
Test, don't guess.
I use a nice old VAR alignment tool for the check, and do the adjustment when the fork is out of the fixture. Find someone who is familiar with doing this, most young wrenches never learned any craft.
John Jorgensen
Palso Verdes Ca