I've got an old calculating machine here that must be from the 20s, 30s or 40s. It belonged to my grandmother. It's made of metal, shiny black, heavy, with a whole bunch of numbers and metal sliders and little handles you turn to make it work. It adds, subtracts, multiplies, and divides. Sort of like a primitive mechanically operated math computer. Boy, is it ever heavy!

It was apparently made in Goteborg and is under the brand "Original Odhner".

I should probably try selling it on Ebay, but shipping it would be costly.