I examined a Navy today that I think is legit - following Tom A's guidelines except for one thing that I observed that troubles me. In the frame ears there are striations, not circular marks that indicate original manufacture. In fact, I noticed these striations on my 1916 DWM, a 1917 DWM arty and this gun. So, I shall conclude that they are all refinished? I unfortunately goofed up on the pix, so the attached is the best I could do.
Sorry for the 700K picture. I will shrink it when I figure out how to do it.
www.plgcollectibles.com/images/navy/HPIM0939.jpg
Larger picture above: