Rare deco vintage Hammond clock without hands, ball bearing clock prototype

Very unusual old Hammond clock for restoration and repair - it's a ball bearing clock, without hands to indicate the time numbers. Two balls run in tracks around the clock face, and the clock is made to stand face upwards on the separate stand.

We haven't been able to find any information about this clock at all, and all we know for sure of it's history is that is came out of the estate of an antique dealer / collector from Rockford Illinois. It might easily have come straight out of the Hammond facility in Chicago, perhaps a prototype piece?

The reverse of the clock is marked Remembrance, and marked with the Hammond logo - Hammond Products Engineers and Manufacturers. The face is marked HOC.

The case is black bakelite or an early plastic, 6 1/2" in diameter. The face cover is glass. The face cover and clock housing have scratching and soil, we've left this just as we found it.

The ball hands have visible rust, and we have no key to test this, even if we dared.

It's a job for a clock fancier / clock specialist, I think - this is a fascinating piece and we don't want to risk damaging it more than time has already done. I think it's safe to say that this isn't in running condition as it is now.