I could not find the release button at first. I looked at the other known Stonesifer rifles, then at the Daniel Marker guns since Stonesifer must have been associated with him/them or trained by them. I finally figured out the patchbox release "button" is under the patchbox's top side leaf near the butt plate edge. That portion of the side leave can be pushed inward slightly, kind of springy feeling. But I still can't get the lid open!
I'm still amazed at the quality of the patchbox when compared to all other known Stonesifer rifles. He was a great engraver, equal to, or slightly better than, the best of the Markers. His cheekpiece eagle is superbly engraved, and a couple of his other guns have similar well executed eagles in the cheek.
Shelby Gallien