My experience has been the barrels either had a dent lifted , then filed and now require finishing or they had external pitting struck off and require finishing. But if it was pitting, be very careful about wall thickness. A thin barreled gun can be sold it the bores are still in proof. If the description also states walls below recommend thickness be very, very cautious.
The question becomes is this gun at the auction because the owner did not feel comfortable shooting it because it was so thin and did he decide sleeving it was not in his budget? Sleeving in the US is a very difficult and expensive option. Don’t buy a money pit if you can avoid it. Been there and still doing that.