Leon Hatot ATO Clock Prior to 1928

Over the holidays, I purchased a ATO clock from a vendor in Talence France on eBay. It was certainly non-descript from the front of the clock but the back panel had a name plate on it. The movement itself was not marked in Hatot's usual spot in the upper right hand, instead the movement was marked on the back. The address was "23 rue da la Michodiere, Paris". From my research on these clocks I know that Leon Hatot had to move his enterprise from this address in 1928, so the clock was probably manufactured before the move. The movement is marked 874 a really low number. It also features claps, instead of the tedious screws that normally hold the movement in the case,
The interesting thing about the name plate on piano hinged back, beside being piano hinged, is that it has a moveable magnetized spinner and markings under it to supposedly to make it go Fast or slow. When I opened the back up there was nothing on the back of the door, but the spinner is even with the magnet pendulum in the movement.
The small spinner magnet on the back of the case serves to either speed up or slow down the magnetic field of the main magnet pendulum (depending upon orientation). So at least in theory it should serve as a means for fine regulation.
The clock appears in Hatot's 1929 catalog. The clock ran from the moment I took it out of the shipping box and hooked it up to a battery.