I think a lot of the confusion comes from some of the kit and stock/component descriptions in some of the vendor's catalogs. As Dennis pointed out "southern mountain" is not a specific type or style of rifle. Really, "Tennessee Mountain" is not either, as there are a number of different regional styles within the "Tennessee Mountain" area, although they do share some similar traits from locale to locale. And the components for any given style are not always based on what is correct, but rather what is available and fits. So it results in a lot of misconceptions.
On the other hand, some vendors focus on a specific style and get it right - Dennis Glazener's Gillespie rifle sets are a good example - all the parts copied directly off originals of that particular style.
In general, when you look at originals, my experience has been that those that fit completely inside a definitive set of parameters for what we associate with a given style are more the rarity, although they tend to be the first pieces that many collectors gravitate towards for many reasons and that is why those are the ones we usually see in books - i.e. they are identifiable and thus we tend to view them as the archetype for that style. However, those pieces that exhibit mixed characteristics from several makers or areas are, in my experience, more common and they are fun to study as they represent a bit of a puzzle and sometimes turn preconceived and accepted notions upside down. I think we are just beginning to scratch the surface on understanding the spectrum of rifles made in the southern Applachians.
