Checking starter ring gear clearance on 99s10

I just bought a 99s10 4cyl. automatic w/75,000 miles on it. I had it on a lift yesterday and was looking at the starter teeth on the flexplate and they looked rough and when i ran my finger across them i felt a burr on the leading edge of them since you cannot see the clearance between starter gear and teeth on flexplate, how do you check?I guess you have to go by the sound of the starter engageing I am tempted to pull the starter and look at it and replace it with a new one and file the rough places off of the flywheel.what would you do?

sounds like somone started the truck when it was already running a few too many times.