Not all that common, but this is the 2nd to pop up on eBay in the last few months. I've written about both of them.
These are part of European dance organs that were used prior to WWII in dance halls. Check out the following 3 articles in my blog for more info: 1, 2, 3. My favourite is the Dacap version (post WWII) that uses robots playing real Keilwerth Toneking saxophones. These are the ones shown in link 3,
Also used in fairgrounds. If anyone's in the UK/West Country and wants to see one in action (and a theatre Wurlitzer), check out Paul Corin's museum, (Magnificent Music Machines) it's well worth a trip, not fat from Looe. Paul's incredibly knowledgable and enthusiastic.