It is a Kundo. The "structure" comes from a Kundo Quartz that I got from an aunt of my wife. It didn't work anymore. I once bought a Kundo mechanical movement for 2 or 3 bucks and forgot about it. I put the hands on it recently and assembled the clock and with the proper torsion spring it started almost immediately (thanks to Charles Terwilliger's book). I'm now the happy owner of six 400 Day clocks that are running in my house. They are all ordinary ones but I still like them.