This Is a very cool piece. From what I can find, this is a pretty rare piece. It seems to function well. When I push the plunger down, you can hear the generator gears turning. I hooked it up to a multimeter and it is definitely putting out power. It’s got the number 3 painted on the front of it, I believe this always an inventory number for whoever owned it a long time ago. I could not locate any serial numbers on it. There is the one plate on the top of the box that lists the manufacturer, otherwise there are no other markings. It’s very old and shows it age, it has some chips taken out of the wood and the bottom of the pice shows quite a bit of wear. Feel free to reach out if you have any questions. Thanks for looking.