We never really know why a specific rifle that varies from the norm is built that way...but my guess is that there was a reason behind it that is lost to later generations. In the case of this Hatfield rifle, the fact that the barrel is not only octagon-to-round, but also shorter than normal for Hatfield's work (and for most octagon-to-round reused barrels) implies that there was probably some thought behind it...such as reducing barrel weight for carrying the gun on horseback. Close inspection of the barrel shows the joint where the two sections meet is not shaped like a normal octagon/round barrel, but rather the round section buts up flush with the octagon section. I haven't seen that before in an eastern octagon/round barrel, so it makes me think Hatfield did the filing on the round section to achieve some result the owner wanted in his rifle. We will never know what the actual story is behind the barrel...but the way it is filed at the joint creates the possibility that Hatfield did the work...perhaps using a re-cycled barrel, but we'll never know. It simply adds another dimension to the known work of Hatfield, whether done as salvage, or if done with some thought in mind.
There are always at least two markets for these early rifles, the first being the general market, and the second being the local market. I'd guess most non-Indiana collectors don't know who Washington Hatfield was...and those that do probably don't have much interest in his work. But for Hoosiers who enjoy and look for Indiana-made rifles, to find a Washington Hatfield gun is a big deal...and an expensive one. I've never seen a Washington Hatfield rifle with a good nose cap and his trademark iron mounts sell down in the 1K range in the last 15 years. Of course, I've seen a number of "wanna be" rifles sell in that range, where it kind of looked like a Hatfield and the buyer was willing to take a chance on it. If out of state, probably not a great deal...but if from Indiana, a very good buy that's easily resold to other knowledgeable Indiana collectors at a good mark-up. They are not beautiful guns, but interesting guns since a lot is known about Washington Hatfield and his brother Emanuel Hatfield, but very few Hatfield guns ever surface.
Regarding the question about whether a flintlock Hatfield has been seen...the short answer is "no." But, there is one fine, and probably very early, Washington Hatfield rifle with curly maple stock, brass mountings including a capbox, and a number of silver inlays, that has a flint plate used as a percussion lock. The gun has a single lock bolt and was undoubtedly made in the early percussion era...but it could possibly have been made as a late flint rifle with single bolt and double throat cock on a late style flint lock. Another of those questions we'll probably never know for sure...but I always get the feeling, when I see one of the finest guns by a late flint/earily percussion maker, that he probably didn't try to save a buck by re-using an old flint plate, when the gun was one of the most expensive and finest that he ever made. Just my opinion, not gospel on that one. Shelby Gallien