Wiley Horne
David,

“It may be worthwhile to take one of the irons after this is done and make it flaw free again and then actually see what stroke the small lines show up on.”

I would much appreciate your doing this, if you can work it in. Use the 3V. If flaws show up instantly, like on the first stroke, then it’s something the matter with the edge before it is used, or something about the sole of the plane being used, like burrs from filing the mouth or somesuch.

But if the flaws show up only after some passes, then that would reject the plane sole and persistent-wire-edge theory, and argue for particles spalling off the edge
or the ‘exposed aggregate’ theory.

Thanks for your good work and your patience with armchair analysts.

Wiley