For anyone interested, here is a re-post from an old thread on patch boxes from 4 years ago....it is easier to see how I do this on a full scale patch box rather than on the half scale one....(Original thread
https://americanlongrifles.org/forum/index.php?topic=42363.msg415586#msg415586 )
"My personal take is that the guys who built these things 200 years ago were....a) very clever.....and b) made their guns the best way they knew how. I try to do the same while keeping within the framework of building an 18th century rifle. As for patch box hinges, I have bent them, but only at the edges....I always keep the center / working part of the hinge straight. The following has become my favorite way to do this after seeing a photo of an original with a separate riveted on hinge.
I make the hinge (as wide as the patch box door) from two pieces of 1/16 inch thick brass plate and two lengths of 3/16 inch (or even smaller) diameter brass rod, each the full width of the hinge. I put both pieces of brass rod in the lathe in turn and drill a 1/16 inch hole through them lengthwise for the hinge pin. I then silver solder the two rods to the two pieces of brass plate. Then I cut away alternate pieces of the brass rod to form the hinge knuckles. All of these parts are nice and straight, so this work is easy to do.
Independently, I bend both the patch box finial and the door to match the contour of the stock as closely as I can. Now, I file the plates on the hinge sides to match the contour of the underside of the door and the finial. The hinge looks like this at that point......
![](https://preview.ibb.co/eHo0mk/IMG_2336.jpg)
![](https://preview.ibb.co/jAcRRk/IMG_2333.jpg)
At this point, the hinge halves can either be soldered to the door and the finial or they can be riveted. Both are traditional methods. Now I have a door and a finial that are curved to the stock but a perfectly straight hinge. But it looks like its curved somewhat because the surrounding brass is. If you want the hinge to look even more like it is curved, file off a little of the brass hinge knuckles on both ends. Here it is just before assembly......
![](https://preview.ibb.co/cPmaK5/IMG_2332.jpg)
And here is the finished patch box......"
![](https://preview.ibb.co/bZgxXQ/IMG_2343.jpg)