Hi,
It looks to be a pattern 1769 short land musket and is in pretty good shape. The critical measurement is length of barrel, which seems to be 42". The wrist plate indicates company "F" musket #1. The regiment number or name may be engraved on the barrel. These were used during our Revolutionary War, first being issued to light infantry and then later phasing out the older long land muskets from the other ranks. We don't refer to these muskets by models because they were never designated as such. They were the "King's Pattern" muskets and referred to as the old pattern or the new pattern when a change occurred. Nice gun and thanks for sharing.
dave