Knife maintenance tool

[Dave Pagel]

I have a few old Marbles knives and a few other stacked leather handle knives.  I see on the top of the handle there is a slot that looks like you can tighten a nut that keeps the stacked leather as well as the rest of the knife tight.  Is there a tool I need to get to use this?

D.P.

[Lin Rhea]

I've not worked on these but I would say that there is a tool similar to a screw driver. Maybe a split screw driver. My first thought would be to file or grind one out of a piece of scrap material.