The 38-56 chambering for the ’86 is fairly common. Not sure what they mean by a “flip up” sight, but they’re probably referring to the very common ladder sight. More importantly, what is NOT common are fairly high condition 1886’s. So if there was a local auction that advertised an 1886, I’d be checking it out for condition. Sometimes, people get lucky and it is either a high condition one, or a deluxe one, in original condition. If that is the case, I’d be bidding on it, but that is just me …. 

Probably, but make sure it is factory checkering. If it falls in the1-156500 ser# range You can probably get the factory information on it