Garry Bradbury had one of these, it appears on several of his recordings (including The Elephant’s Four Legs). I also used it to create sounds for a musical machine tucked into one level of the HH game. You push keys, the little heads open up and an electric motor spins wheels against small bells, which make a continuing metallic ringing sound. Unfortunately most videos will only carry the motor noise not the bells (the machines being so old).
I wanted to wait for a working machine but the only near working machine would have been $150 by the time it was posted here from America (mainly postage). Instead I paid $10 and will have to go in and replace the motor and the rubber band before it makes a sound. Shouldn’t be impossible but might take some time.
Why is this a good toy? Unique design. Weird way of making sound. Polyphonic. Nothing quite like it. Calling out for a VST I think.