Great example! Seems you gotta get aggressive somehow and get some middle out.
The old pasted-strop wear is nobeno, IMO.
I used to have a good rhythm doing it with a Dremel. Lots of work no matter how you do it.
A belt-grinder and experience comes to mind!
The old guys did it with stones.
Seems like Magpie was working on that?
Well, You get my drift! :D