I've been thinking about this for some time now, just what, exactly, did our forefathers lap their hones with? I'm quite sure that they didn't have to have something that got within .0001" from perfectly flat! So how did they get their close shaves with something that wasn't lapped properly? Could be that they apparently did quite well with what they had, as did the barbers of that day. Just look at old barber hones, they almost always have a dip in the middle, and yet, still honed razors. Maybe we put too much emphasis on this accurately lapped hone business when just a little expertise would do the trick.
Like I said, this is just some ruminations on the subject.
Fred