I believe the architecture (the comb curvature & Lehigh lower stock curve) say eastern PA. Many southern hunting rifles came north with the end of the American Civil War but this may not be one of them. The grease or tallow hole is cut straight in, shows no sign of ever having a knot and measures 11/16" deep, 5/8" up & down and 1 1/4" across. Inside the hole has it's irregularities as if finished with a small knife yet smooth with likely built up tallow becoming waxlike...and pitch black.
That is definitely an eastern Berks or Northampton area utility piece. Also, I think it's a big mistake to assume that because the rough forged guard is a secondary replacement, that it must have gone south. I've played with quite a number of these eastern PA 'barn guns' that had very similar iron strip guards, or piece of iron strip used for buttplates or partial buttplates, or for all kinds of things. Utilitarian is utilitarian and I don't think there is any regional dictate on that aspect. So rather than a fiddle and buck dancing, I would personally envision a hurdy gurdy or (later) accordion and a big pile of sausage!
Wabeek,Thanks for sharing the photos of this piece. I came into a similar rifle last year and am always interested in see others. Consider me curious, what is the shape of the barrel tang on your rifle? The one on mine tapers to a point.Thanks Again,Kevin [/quoteKevin,Tang is a gentle 3 1/4" taper with two screw holes (rear one empty) about 1/2" apart. Old reinsertd broken piece repair between tang & lockplate maybe evidencing older lock took a hit.