I thought this would illicit more responses by now. Far be it from us, or at least ME, to re-write the "bible" by Kindig! I agree with the previous interpretations all right. With the exception of Tims part about "superior architecture, fit and finish and complementary elements, etc." While this is very true, many, many Pre-Rev guns also fit in this description.
When I think of GA rifles, my mind pictures rifles becoming much slimmer and graceful, with smaller calibers and adorned with a profusion of fine carving, fancyful engraved brass patchboxes and more numerous inlays. This going on until the percussion ignition was adapted. Kindig included Bedford rifles in his book and I guess he considered them in the GA as well even though they are mostly developed in the percussion era after the 1820s. I don't really consider them GA, but I do recognize the vast influence they had on gunsmiths who migrated westerly into Ohio and beyond. Moreso than the GA architecture.