A used Daimler V8 Smiths Rev counter part number RV7413/06 or Daimler part number 9720 it's been tested and it responds accordingly when you apply a voltage to the terminals. The item is about 60 years old and will probably benefit from a good service.

The bezel could do with a rub down and a fresh coat of paint and the inner bezel/cloaking ring could do with the same as the paint is flaking off (see pictures)

A couple of very small scratches on the glass from years of storage in an old box but other than that and with a bit of TLC this could be a very nice usable item.

No clock I'm afraid.