DanC

You could try wetting it (not soaking it) and ironing it. Yup - iron. Place a piece of material under the iron first. Also, instead of attaching it flat, put it on, glued and all, then fold it into shape and let it dry that way. Use a test piece to see if you like how it turns out.

I have this stuff - and it is spongy not stiff. Haven't tried to skive it - could barely cut a straight line with it due to its springiness. You will need a very sharp and honed skiver or head knife, which I think would be better as it has a type/shape of blade that is easier to control for this type of stuff. Skiver is good for stiff leather as you use it "sideways". A head knife is straight on. Use a Metal straight edge and clamp it to the table (if possible) and run the blade against it to try to get a straight line. Practice on a junk edge to get a feel for the cutting. It may take a few cuts rather than one long straight full cut to get what you want. If you can't clamp at least draw a line to keep things straight. You might have to buy a hunk of 1/16" or 1/8" aluminum for the straight edge if you don't have anything that you can run a knife against.

The type of hinge you used is very sloppy. It can be made a lot better but a judicious use of a wide piece of metal (just as wide as the width of one of the hinge leaves) and gently tapping each one tighter against the pin. This will tighten up the play. If the leaves already touch, then drive the pin out and put in a bigger pin. A larger nail and a little drill press work should suffice to get you the right size pin. When making the pin, make it just a bit oversized so it can be driven in. It will then make a tight fit on its own. This would be true even for a piano hinge, but they are a lot less sloppy by design, but would look better and give more hinge area and less slop.

So - How many tools and hours does it take to make a toothpick holder? I'd show more pics of the work involved but pics are too large. Have to figure out how to minimize the size.