FB2's photo shows a good reason to collect all the details possible to have a good out come. Barrel address, barrel configuration, length, cut or original, which sights, other parts attached or missing and caliber.
Hmm.. maybe somebody we know can go through and weigh the common combinations of sights found on 1899's and 99's?
Most barrels I would expect to belong to a rifle, and I'd rather have a serial number than a barrel address. But in the case of loose barrels like FB's, barrel address is probably the best we can do.
