I'm working on a guitar that has some file marks on the ebony fingerboard from having the fret ends done. It's nothing absurd or eye catching but I figure I may as well fix it if there is a good method. Anyone?
Yep, I see them. From dressing the ends no doubt. If they are shallow enough they can be carefully scraped out by a razor blade with a burr turned on it. Follow that with some grey scotchbrite and a bit of oil and no one will ever know.
The fret ends could be rounded better. Actually, it's almost impossible to round the ends to a "spherical" shape without leaving some marks on the fretboard and bindings, but there's nothing unusual to scrape them off with a sharp (or even burnished like a scraper) blade.