For an orginal factory-finish piece (i.e. not a re-do), I would look for "halos" on the stampings of serial numbers and bore on the barrel underside, "halos" on the 4-digit serial number on the left side of the receiver, and "halos" on the little 2-digit serial number stampings on the small parts such as the breechblock, front toggle, etc.
Strawed parts should have an old, weathered, oxidized, and sometimes worn look as well...with some of the straw color going dark and even grey in color. Pattens of wear from contact with fingers and thumbs on the right side of the trigger and the thumb safety lever also...
BTW...here is a nice one to study with good detailed photos. Ad said it was refinished, but it was not and a member on Jan Still's gun board won it for a bit over $ 2,000.00...a very good buy in today's terms.
It even had some traces of fire-blue finish left on some of the small parts of the rear Artillery sight, sear bar spring, and some of the toggle train pins and magazine release spring...
http://68.167.203.107:8050/FMPro?-db...12584808&-Find