Looks like a variation on the ear shaped drivers Yamaha made many years ago; late 60s or rearly 70s as I recall. Regular dynamic motor with a strangely shaped "cone". I think Yamaha was trying to spread out the vibration nodes.
Yes i have seen one of these before and replaced the voicecoil. I think it is from an organ or some musical equipment. The cone is made out of polystyrene and the frame is cast aluminium, sounds terrible for anything except instruments.