I'd like to know, too. I have similar hardware on a 'sewing cabinet' that is shorter than the machine cabinets. It has what looks like two drawers, but the bottom is a lazy susan type that swings out. I think that the original hardware on part of it is long gone as the wood is chipped out. It looks like the metal piece may have been installed lopsided. I would think that it should be parallel to the front and back sides.
Janey - Neat people never make the exciting discoveries I do.