Clean it up (if that's not done yet). You can probably take out the rough spots with Flitz or bore lapping compound. That is, if your "feeling" rough spots when you ram a load down the barrel.
I say take it out 'n shoot it. See what kind of groups you will get. I have a T\C Hawken flinter barrel that had (has) some pitting in the middle of the barrel. I used some lapping compound a few years back and got the rough spots out. It shoots as good as it did when it was brandy new. No where as good as my Green Mt., but still, it shoots.
Dave