EIEIO,
OK, I'll explain how I build those boxes. First, I'll admit that it takes more than a scroll saw. In my case, I also used a table saw (actually a band saw would work better but, I don't have one of those
) and a drill press.
I usually use a large, solid block of wood but, as you can see (looking at the striped box) I sometimes will glue up a blank of suitable dimensions. Once you have a blank squared up, (be sure to mark the side you want to be the top) slice off (re-saw) about 1/4" off the bottom using the table or band saw (try to keep track of at least one end of the block also) and 1/4" off the top. NOW, re-saw another 3/8" off of the "top side" of the block.
Drill four holes (one in each corner of the body of the box) about 3/8" from the sides and ends. I used a 3/4" forstner bit all the way through the body and then with the scroll saw, I cut from hole to hole and remove the center chunk and toss it.
Using the 3/8" slice and tilting the table of the scroll saw about 10 or 15 degrees, lay out and cut a line from the "front edge", along the sides to within 3/8" of the "back edge" so that the top face is about 3/8" wide and the bottom face is about 3/16" +/- wide and cut a square "U" out of the 3/8" slice. What your trying to do is make is a sliding dovetail joint for the top to slide into.
Now carefully re glue the bottom 1/4" back onto the body and the upper 3/8" around the top edge of the body along the outer edge of the top. Now glue the center piece of the 3/8" back to the top slice being careful that it lines up with the dovetail. I usually just assemble the box like it will be when finished and make sure that it slides open and closed easily before the glue is completely dry.
Sand smooth and finish as desired.
It now looks like a solid block of wood if the grain matches fairly close.
As for the magnets, rare earth magnets are very expensive for my taste's so, I just buy those little "push pin" looking things that are used on refrigerators and crack the plastic off and use the magnets. I use two magnets, one in the lid (top) at the front edge and one in the front of the body making sure that they line up and the pos./neg. line up. Those little magnets measure 3/16 in diameter and 3/16" in height so I use a 3/16" brad point bit to drill the holes for them and epoxy them in the holes.
I hope this helps some. If you would like a picture or two, I'll b happy to post some close-ups of a walnut one that I store my Tootsie Roll Pops in.
DARN! I,m long winded! I just hope some of that makes sense to you.
Rog