Yes it does - and I wonder, you may well be right. It is exactly at that location where the rawness is generated. I shall check tonight to see if I run a hand over them I can feel any raised edges or roughness, then perhaps a sharp knife? How does one smooth out a rough spot on leather? First need to check though, and perhaps you can only feel the roughness when one's weight is applied. We'll see...

Thanks - good idea...