Gary,
I can easily agree. I have always associated that lock engraving with a post Rev war date too, although I was thrown by the earlier shape of the lock plate and cock. In fact there isn't anything about this gun that couldn't date it as late as 1800-1810. The buttplate finial is fairly short too, leading me to believe it may be a little latter than Rev. war.
Regardless, It's a great untouched gun, that was built with military as well as civilian use in mind. I still think it's a New England gun, although there isn't much to base that on other than a cherry stock.
I believe the lock is by William Ketland by the stamp inside, anybody have in dates on William Ketland & Co.?