I washed the bore and ran my $10 ebay USB bore scope down it. There is visible rust for the first 2.5" where the charge sits, rifling is thin but visible. After that the bluing appears with small rust spots all about, rifling looks ok. Then at about 7" from the breach there a a few rings of rust with rings of blued bore between, rifling is clearly visible throughout the rings. After about 8", it looks pretty good, 90% is my guess. I don't see any evidence of pitting, only surface rust.
I don't like the look of the crown, which is absolutely critical in modern rifles, not sure how much it matters with a patched ball. I may consider having it recrowned if the rest of the project goes well.
Now I need to find some patches and balls and give it a try!