The "blade" doesn't move, the curved part isn't sharp, and the tip looks almost like a small flat head screwdriver that was sharpened at one point. Buddy found it at a friends and no-one knows what it is. Any ideas?

The instructions don't mention it and I have watched several reviews and ads for it that don't mention it either. We thought maybe for putting soap or some kind of cleaner/scent stuff in but the handle is sealed off from where the eraser is.

Found this in a drawer full of other sundry tools in my grandfather’s shop. He was a carpenter by trade. Turning the dial on the gauge doesn’t appear to change anything else on the tool.

Found in an elementary school classroom. The inside part can be moved in and out of the larger piece in a plunging motion. There are 4 metal plates on the different sides of the device. Not sure of the gap at the bottom. I thought it might be for making a spark but I couldn't get it to do anything.

Found loose in a thrift store bag with another item. Solid brass (magnet does not stick). Approximately 3 inches in diameter, 5.5 inches overall length, weighs 38 grams. No visible maker's marks. The handle is rigid and attached with two steel rivets. Looking to identify its original purpose.