Look at how the MRRW built Hatfield was made with a Green Mountain barrel and L & R locks and triggers. Being how popular they were I'm surprised that this new and vastly improved Hatfield rifle didn't survive. I don't know, more availability to custom makers the 'reputation' that the older Hatfield Rifle Works earned for themselves with vendors and other black powder enthusiasts, I don't know.
But if you look back on it, Green River Rifle Works is gone, Ozark Mountain is gone, Sharon Rifle Works is gone, Hatfield Rifle Works and Missouri River Rifle Works are gone, the only one to survive was Tennessee Valley Muzzleloaders and Thompson Center.