The grain pattern on my current build is very contrary around the lock panel and as I began inletting lockplate I was having a lot of trouble with tear out no matter how keenly my chisels were sharpened. I know no one sees behind there but my inletting job was looking horrible. What I needed was a flat bottom bent riffler file that I didn't have.
I decided to see if I could make one. I used an old allen key wrench and forged a blunt taper on one end then fullered down the shaft just a bit back from the end to leave a sort of bullet shape. I flattened this to sort of a leaf shape and annealed in the ash drawer of the wood stove. I filed it to shape and honed flat on the bottom.
Next I forged a lttle chisel out of tool steel and ground to shape with the face a little rounded over and the back flat. I hardened the edge.
I clamped the riffler to a block of lead and cut in the file teeth. This was a tedious process as I found that the chisel edge chipped and had to be honed after each cut.
After I cut the file teeth I cut off the stock and drew a taper on the opposite end to accept a handle. I clamped the little leaf shaped riffler head in my copper lined vise jaws to protect it and heated the shank to bend and shape the offset. Next I heated the file end only and hardened in oil and added an old file handle. Although it looks a little rough it works great!
In no time I was able to smooth out and level the bottom of my inlet. I do have a profound respect for the the tool makers of old who hand made files though.