Decided to make 1 hinge 8” long that would blend into the form of the box. I roughly followed the process described by Gary MacKay in his 2005 Scroll Saw Worksop article. After milling the stock and before radiusing the barrel of the hinge I drilled .120 diameter holes in 1/2 of the hinge.( the part that later will become the barrel segments on each end. I will use these holes to pilot into the internal barrel later to ensure perfect alignment.
After cutting out the appropriate segments of the barrels and filing/ sanding to rough in the 1/4” radius I cut down the piece in half to produce the two hinge segments. A few minutes with a chisel and the two pieces fit together.
Next to transfer the holes for the hinge pin. I clamped the two pieces together, clamping the hinge upright in a machinest vise and using the previously drilled holes as pilots drilled the holes into the ends of the inner barrel segment.
A bit more filing and sanding to blend the barrel radius and it’s starting to look pretty good.
And it functions smoothly.
Next to cut the mortise in the back of the box to accept the hinge.
-- Dan, TN