Clarke 6 inch metal grinding wheel (East Hendred OX12)

This is a 6" bench grinder / metal grinding wheel with a coarse and finer wheel by Clarke. It is in full working order. It needs clamping / screwing down when in operation otherwise it migrates across the surface. There are four screw holes for this purpose. One speed. The transparent plastic safety shields that mounted on hinges above each wheel are missing and so safety glasses are essential when using it.