Bob: before you start filing and drifiting, let the piece break in. One reason for a lack of accuracy out of the box is that the slide and barrel have to 'wear in' together and seat with each other properly before the piece is free of bugs and the like. Quite often you may have slight burrs or sharp edges on the bands on the barrel where it mates with the slide, and the same on the slide, so even though she goes into battery and is safe to fire the barrel may not be properly seated against the slide. When gunsmiths work on 1911s to improve accuracy the make certain the bands on the barrel and the cuts in the slide for those bands (er whatever they are called) match up perfectly - then you know where you have to work on the sights.
Also, after she is broken in if she still shoots low you may be able to correct that with a shorter barrel link but, let her get broken in first and then fiddle with it. HTH. Mikey.