Just to clarify a comment above, though, tombstones are usually very easy to replace, and cost just a few dollars at the hardware store. Just because they're wrecked doesn't necessarily mean the fixture is complete garbage. As for ballasts, I've changed more than I care to count, but it's my job. In any case, if you're going to LED, anyway, compare the price of a couple of T8 (or T12) replacement bulbs with the price of a new fixture.