Now there’s a project for you!  Good for at least a few weeks of
procrastination from a more pressing project.  My opinion is that it is
unlikely a plane maker capable enough of making a low angle wooden miter
plane would make the mistake of miscalculating the placement of a natural
defect so close to the mouth.  Whatever it was seems to be responsible for
that  huge furrow as well.  How big is the mouth when everything is
assembled?

Paul, getting ready to head down to the shop in a sip or two.