Here's a dovetailed knockbox I completed for a client in Florida. It's made of some nice air dried American Black Walnut from Amish sawyers in Ohio. Finished with a few coats of Osmo. A little metal housing rests inside of it.
I like to cut two rows of dovetails at one. This saves time and makes sure your dovetails are identical. Then I use a shopmade dovetail alignment board to perfectly transfer the tails to the pins. If you don't have one of these I highly recommend it, it makes a big difference in efficiency and quality of transfer.
This is something I try to do as often as I can. It looks nice if your board wraps around the box so the figure and grain all flow around the corners. Here's a photo of the metal insert housed inside the walnut box.