Thank you!
Regarding the patchbox construction: I didn't take many pictures, but I will do my best to explain the process that I used. First of all, I would have preferred a single piece of wood, but the leftover piece of maple that best matched the stock was too thin, so I had to use the two-piece method.
First, I blew up a scanned picture of the lid to the appropriate size. I had to play around a bit with the x and y axis of the photo to get the proper length, width, and overall size for my printed pattern.
It is important to make sure that your lid points to the proper landmark further forward on the gun, whether the beavertail, or rear point on the lock, or whatever the gun that you are copying requires. I determined where the rear end of the lid looked best on the buttplate, put a mark at the center of this location, and then drew a pencil line from this mark to the center of the beavertail, or whatever it was on my gun that the lid needed to point toward. I also drew a pencil line down the center of my paper lid pattern and made sure this always lined up with the pencil line on the stock.
With the lid pattern in position on the stock, I carefully traced its outline on the wood of the already shaped butt. I then flattened the wood between the lines--and only between the lines. The natural curves of the rest of the butt must be maintained. You have to use a straight edge over and over across all possible angles to make sure that this area is PERFECTLY FLAT. Here's a picture of my rifle after this was almost complete:
Next I redrew the center line on the now flattened stock, and then I used a forstner bit (that was about 3/8" smaller diameter than the vertical width of the lid) to drill a series of holes to create the actual box. Chisels and files were then used to turn this into a neat, straight-walled depression in the stock. After this, with the buttplate off, I used chisels followed by a triangular file to form the dovetail in the in the stock. With the buttplate back on, I then carefully filed a matching dovetail into the buttplate with flat and triangular files. Here's a picture at that point:
(NOTE: I'm not sure if you can tell from the picture, but the dovetailed "rails" on either side of the patchbox are not parallel. They are a bit closer at the front end of the gun than at the buttplate end. This will cause the finished lid--similarly tapered--to tighten into position as it slides home.)
Next, I redrew all of my pencil lines on the stock, and then I used the paper lid template to cut out two pieces of wood from leftover curly maple with my band saw. One piece was about 1/2" thick and was for the top of the lid, and the other piece, about 3/8" thick, was for the hidden, sliding bottom part of the lid. I worked hard to make the figure/stripes on my lid line up with the stripes on my stock, but only because of personal preference. A lot of original lids seemed to have been made without considering the figure.
The sliding piece was formed first. I used sandpaper on a very flat surface to make sure the bottom of this piece was very flat. Then I used files and a lot of test fitting to get this piece to slide perfectly into position. At this point, it stood a bit proud of the surrounding stock wood, and it also stuck out past the buttplate. I very carefully filed this as flat as possible, and level with the surrounding stock wood.
Then I formed the top part of the lid using files, chisels, gouges, and sandpaper. I again used sandpaper on a flat surface to make the bottom of this piece as flat as possible. After slightly roughing the mating surfaces of the top and bottom lid pieces, I used a thin film of epoxy (could also be hide glue) and clamped both pieces together with the bottom piece tightly in the dovetails.
After the epoxy was cured, I cut the extra lid material off flush with the end of the stock. Here's what the cutoff looks like, in cross section, to give you an idea of the relative thicknesses of the two pieces:
I then positioned the end of the patchbox lid on a piece of brass bar stock and traced the outline. This was then cut into rough shape with a jeweler's saw and files, and then I attached the brass to the end of the patchbox lid with small screws. These are tightened into slightly countersunk holes in the brass and then filed off smooth, so they look like this:
Once the brass and wood components of the lid are assembled, the brass end is CAREFULLY filed to match the contour of the wood and also to fit in the dovetailed opening in the buttplate. With the lid clamped in the closed position, the brass of the buttplate and the brass of the lid are filed and sanded to be level with each other (This picture is actually taken much farther along in the process...):
The final step is the spring. You can make one from a nail or buy one. It should look like this before it's installed:
A groove needs to be formed in the bottom of the lid just wide enough to let the spring be pressed into the wood and brass without binding. The groove should be approximately 3/4" shorter than the spring, with vertical walls. To attach the spring, its pointed end is heated quite hot and then pushed into the wood. You can see a bit of charring on the bottom of my lid from this process:
Finally, a notch is filed in the spring to catch the buttplate, and the interface between these should be polished smooth. I actually used Kasenit to harden the head and notch of my spring, but I'm not sure if this is a good idea or if it will accelerate wear on the brass of the buttplate. So far it seems fine. When done correctly, the lid should "click" into place just as all of the wooden dovetail surfaces engage tightly. There also needs to be a notch chiseled and filed out of the rear of the patchbox on the stock itself, or the spring won't engage the buttplate. You could also just make the patchbox extend so far to the butt that it almost breaks through the butt, eliminating the need for a notch. But I wanted to retain a bit more wood for structural integrity, so my rifle required a notch. Here's a picture:
I hope this is helpful! It was actually a couple of years ago or so when I completed this step, so my memory is a little foggy on a couple of details....
