I'm more with Randy on this one. The heavy, nearly wedge shaped blades were harder to hone and the typical home user did whatever was needed to get the edge to shave again without any of the science we are apply to it as a hobby. A dished stone, the spine lifted up as in sharpening a knife, whatever it took. The result is odd spine wear, odd bevels, etc...

I have a few early wedges that still shave that all show odd wear. one even looks like it was taken to a large round whetstone to add a bit of hollow to it at some point and looks terrible.....it also came out of it's ancient coffin shaped case ready to shave!

Tony