For fixing the edge I support Stefan's (mainaman) approach, but that looks to be only one part of your problem..
It looks to me that when you take out the frown you will come in conflict with the heel/stabilizer, which will need to be ground down before you can hone it.
I thought exactly the same. It already looks as though a large part of the original width is gone and fixing the frown will make it even worse. Sometimes you just have to say it's more trouble than it's worth.