Golcher would be late, probably replaced, but it looks like the original lock was also round tailed, which makes me think 1800 at earliest or later in general.
The only "early" feature I think I see is the depth of the molding on the toeline of the buttstock -- it seems to be relief-cut, but that may just be an artifact of the picture and/or a feature that the maker retained or re-employed later. From the other features, I would guess ca. 1810. I wish I had another Shaffer to compare, but 1810 SW Va. wouldn't shock me. What is the evidence the TG was replaced -- it actually looks pretty acceptable?
On the other hand, if the provenance is solid (unlikely), it might tell us more than what we think we know now.
If I had three hands
, I would say that I am a little concerned about the wear on the stock where it looks like the flint hammer stop rubbed, but that is probably due to difference between original and replacement flintlock.