Hello,
In initial prep of an old tool...
That is what I was getting at and not the idiosyncrasies of sharpening in general. And how one maintains tools is really very personal so I wouldn't intrude there either.
But when I first get hold of a tool whether new or used I want to have it technically in shape and a blade with either machining marks or showing pitting from age cannot be given a sharp edge. It is technically not possible. If you want to get a true sense of that, try doing your best sharpening on an old straight edge razor and then shaving with it.
