However, sometimes the sun shines and I find something interesting. A while back I bought this folding mitre box, in most of it's original finger jointed box.

There is a rod, with a decorated head, that stores in the side.

This rod slips into a hole in the front of the box when it's opened, holding the bottom flat.

There are metal guides, one at 90° and two at 45°, slotted for adjusting to the thickness of the saw plate.

Brass studs prevent cutting through the bottom while keeping damage to the saw at a minimum.

I think this is made by the Gem Folding Miter Company, The Alaska Freezer Company, Winchendon, Massachusetts. However, there are several differences between this one and examples I can find online. The Gem boxes came in a cardboard box, the hinges and wood are different, the guides are a white metal, they have a ruler scale printed on the front, and they have a decal. The only mark on mine is the word "patented" stamped on one end, as of yet I haven't been able to find record of the patent or it's holder.

The box has a 3" capacity, too deep for my Lie Nielsen Carcass saw.

When I first got it I intended to salvage the metal guides and install them on a shop made bench hook, but now I think that would be wrong. I'll keep my eyes open for a Gem model to disassemble, this one will stay in its present condition.
