Woodsrunner,
Guy is correct. The group of rifles we refer to as the Rowan School were mostly made by Isaac Ribelin, George Eagle, John Eagle and Leonard Nash. Many of them are dated, the earliest being 1827 and most being in the mid 1830's.
The shape of the stock of the rifle that Rob posted fits that group. The double incised carved line along the comb is matched by a double incised carved line up the bottom of the butt-stock that goes around the front of the trigger guard and returns around the other side. Also of note is the scooped out cheekrest. The one commonly found feature I do not see on this rifle is chip carving in front of the butt plate.
The patchbox is not the normal elongated Christmas tree type found on the Ribelin, Eagle and Nash rifles, but is similar to the earlier Bruner rifles from the same County. This rifle also does not have the fancy triggers you usually find as Guy pointed out.
To sum up, it is a very nice rifle and I would enjoy seeing more photos of it. Rob, does this rifle have any fore-stock molding? I also would like to see a photo of the nose cap as they are usually distinctive too.
Thanks,
Michael