No gizmos or diamonds for me,a big chunk of soft Arkansas stone and a leather strop with green chromium oxide powder keeps my O-1 sharp.

I do something similar for my O1 #5-4, at least at home. In the field I use a diamond type.

I've posted this pic before in the Sharpening Thread .

same here! I use a norton natural stone professional set and a strop with the green compound