Well fellows, this has been fun, and i have a bit more information to throw out after corresponding with the owner. Here is what he wrote concerning the features. "It has a 49" barrel, about 65 caliber. The barrel is English (three stage) and the barrel makers mark (Blackmore) could be as early as 1742, so the gun could be F & I war period. The stock is cherry, I have been told. there are two ramrod pipes, that are small and have that copper look to them as many did. The triggerguard is from the 1680-1710 period (according to Bob Speelman) and the only one that he has seen actually on a gun and not excavated. It is screwed in the front (probably originally for an upwardtang bolt) and nailed at the back. Except for the ramrod pipes (American) all parts are undoubtedly from earlier guns. It is cut for a bayonet and probably saw Rev War service. Also the trigggerguard is "spooned" out with is an early feature. The lock is 7" long." I am aware that this is a fowler musket rather than a barn gun. I just thought i would have a little fun and let the younger guys see that the concept of building a gun w/o butt plate, sideplate, entry thimble etc.(features of a "barn gun") goes way back
I will post some more photos as soon as I can. Keep speculating.