From and older post of mine........
I don't like gaps in the hinge but was never good enough to peen / stake the hinge into submission. Here is an old post of how I do the hinges now....no gaps....
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......
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. However, 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......
And here is the finished patch box......
PS....I have started using ~ 0.030 music wire as the hinge pin and turn the brass rod down to about 0.080 or so. Makes for a much more "svelte" hinge.
