The bevel is filed, yes. It is a very very slight bevel, like 2-3 degrees, Its kind of like you know you did it but can barely see it. The bevel goes from the top surface to underneath it. Think of holding a rule vertical on the edge of the brass and tilting it outward, away from the center, a couple of degrees, that would be the angle of the bevel and what I'm saying is the bevel tucks under the edge not outward from it. Also, I have no idea what type of box you're doing but remember you are working on a curved surface so work accordingly - For instance the "old removing wood from the middle first" then out to the edges technique.
The exacto is one method, "stamping in" is another. The thing is with an exacto cut you can't then go back and wet the edges for a snug fit since the knife slices the wood fibers, with the stamping technique you can as the fibers are only pushed aside and they will close around an inlet when dampened. I use the exacto knife which I am very confident with (I stamp when doing wire work though). Use temporary screws to keep the box in place while you cut, in any case you will want to use some method to ensure it does not move during the cutting. If using the knife tilt it at the same angle as your bevel as you go around, the first cut is very light, don't try and go deep with it. You can then go around again with a deeper cut, or not, according to how confident you feel with that knife but at least you know have the outline on the wood and could go to other tools to deepen the cut, even stamping, its up to you and how you feel. At this point I would go around the inside of the cut with a mallet driven V tool, a veiner, a small one staying immediately inside the cut. This makes removing the wood along the edge easier which I do mostly with a one-quarter or half-inch inch chisels using a slicing motion. Check out Mitch Yates inletting tutorial:
http://americanlongrifles.org/forum/index.php?topic=29664.0A patchbox is just a large inlay with moving parts...
For more on the stabbing technique look at Tom Currin's tutorial:
http://americanlongrifles.org/forum/index.php?topic=29820.0For tools I use the exacto knife and do about 90% of the wood removal with a very sharp 1/4" or 1/2" parting chisel using slicing cuts, otherwise I use a small sweep, like a #3 3/16's" size and a small curved bladed skew like the bottom one on this website, the palm tool:
https://www.toolsforworkingwood.com/store/dept/TXQSS/item/IL-RAYGHS.XXThat skew is really handy in tight places but you have to keep it beyond razor sharp.
After you've gotten your edges defined resort to lamp black or some tale-tale marking agent of your choice to bring the brass down.
Good luck, before you run into trouble ask questions...
dave
