Say a vintage razor suddenly appears in front of you, 1/2 hollow and based on your SRP education its most likely from 1890s. The part of spine that touches the hone is visibly consistant from heel to toe both sides with a flat width of about 2 mm. The blade width is consistant over the length, i.e, the toe is not honed out.

As you consider the flat of the spine, the question is: is this the result of user honing, or, could it be an artifact of the original grind ?