Jim Matthews
These are fine examples : complete and in good condition.

I also use dowel rod wrapped in fine sandpaper for the concave blades.
As DW suggests, a corresponding "trough" is needed for the convex blades.

The first sharpening may require some gentle filing, until you can make the trough.

I use diamond hones for this, the kind that are mounted on plastic "paddles".

To get these cutting well, the sides of the blades should be a little back bevelled.

http://musingsfrombigpink.blogspot.com/2011/01/sharpening-window-into-my-basement.html