Hmmm, a brain teaser for so early in the day. Okay, I'll make some observations. Yes, it is an external screwtip and the base plug looks like it might be an early Philadelphia school style, but they were generally an 'internal type' screwtip. In addition, the horn appears to have had an 'applied band' as evidenced by the distinct change in color, or patina, near the lower staple. Or perhaps, it was indicative of a 'metal band' for some reason, or it is possible that a leather strap was very tightly sewn to keep it's position there. Also I note no incised beads either at the base plug area or the throat that might further tell us what 'school' the overall style would be. The threads also look to be 'more refined' indicating made during the 19th century? From what I know about the different schools of screwtip horns (which isn't too much) this one's a toughie. I would think that this horn was most likely made by a competent gun builder rather by one of the earlier schools. The tip itself isn't a good indicator either as it could have been made as a replacement directed by the owner. After all this, I still would only be guessing where this horn originated from. I need another cup of coffee now.
Gary
