Ah, my error!
As the blades were imbedded in the corks in the drums, and the numbers recorded, they were still in unused condition, albeit somewhat nicked/distorted by the tumbling they received. Upon removing them, some enterprising fellow discovered, upon happenstance, that if he were to withdraw the edge of the blade through the cork that it would in fact restore the edge to usable condition, and in fact improve upon the original sharpness of the edge of the blade.
Mind you, this is hearsay, as the electron microscope was yet to be invented, and there was no scientific proof to verify this observation, only subjective reporting.