Large Mid Century Shelving Unit with 84 Pigeonholes

Large pigeon hole grid shelf unit made in the 1970s probably. It has 84 sections, each about six inches square. The front edges are painted matte black. It's made from ply laminate wood. Probably intended for horizontal use, as there's an extra layer of ply on one long side, slightly recessed to make a tiny base. But it doesn't really stop it from being used vertically, and the construction method actually makes the shelves slightly more robust that way round, though they're strong enough for most normal use. I recommend fixing to the wall if you have it vertically.