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I can't say, but I'll throw some GOOGLE FU on those numbers & Columbia tonight,,,see what I come up with.

Oh dang,,,that's a reflection of a painting on the wall,,,,:rofl2:

The first one is hard to tell with that pic, but a close up of it's sides might help,,,the second is a dual grit Carborundum or Norton Crystolon (Norton's word for silicon carbide).
The third,,I...