I think you may have a really old or customized jeweler's forming block. Forgive me if you already know what that is, but if you don't, you can see some in a Rio Grande catalog online. The large grooves on the sides are for making tubing- you start with a piece of flat sheet and with a wooden or metal dowel, you start at the largest and shape it there first and then you get progressively smaller until you have come to the smallest point you'd like to and of course, the two sides meet. It is a very time consuming process. The middle holes are good for insterting ball stakes, mushroom stakes and others of different sizes used for shaping jewelry and other items. If any of those holes are tapered, Then another pointed piece that fits into it can be used as a punch for bezels in order to set stones without having to wrap and solder.

Hope that helps. Of course, I could be totally wrong, too.

Emily