Hi Flint1,
TRS did make copies of the Ordnance issued Ferguson in the Milwaukee Public Museum. The only other known survivng Ordnance Ferguson is in the Morristown National Historical Park in New Jersey. I've built 3 Ferguson rifles using TRS parts and the castings are generally excellent.
Mine are copies of the Morristown gun, which I handled and examined closely. There are lots of stories and myths about the Ferguson rifles. I've never seen any documentation that the survivng rifles came up from the south. Moreover, if some of Ferguson's men kept their rifles it was in direct violation of Howe's orders. There are those who want to believe Ferguson rifles were used at King's Mountain? The only British soldier at King's Mountain was Ferguson and he did not have a rifle on him when he died. The rifles were originally issued to British soldiers so to have been at King's Mountain, they had to be reissued to loyalists. There is no surviving documentation of that but it is clear Ferguson's Amercian Volunteers were armed at Charleston with the usual period arms and perhaps some pattern 1776 muzzleloading rifles.
dave