In the process of patching together the only ribbon I have for my Monotype, some of the holes have been blocked and needed to be re-punched. Furthermore, repairing the edges of the ribbon requires re-punching all the tractor holes. Finally, modifying a ribbon for a new set size can be done by altering the punches that set the justification wedges.
To do these jobs I made myself a small punch out of steel. It is just a short piece of steel rod with a hole drilled down the middle and the end tapered to form a cutting edge. I started drilling the hole with a #47 drill since this seemed to be the best compromise between the three different hole sizes encountered on a ribbon, but that drill broke. After removing the shattered pieces of the drill bit, I used the next size up (#46) to deepen the hole a bit, then drilled from the back end with a larger drill that was less likely to break. I tapered the end finishing off the job using a file.
At first I was just using this held in my fingers but that got tiring pretty quickly, so I found a way to fit it to a handle. Using a bit of paper I jammed it into a socket which in turn fits onto a screwdriver handle.
Punching holes is a simple matter of pressing this cutter down with the ribbon sitting on a cutting mat. The chaff pushes up through the central hole and comes out the back of the cutter, so occasionally I have to remove it from the handle to clear it out.
This is not hardened steel, so I expect it to dull quickly, but sharpening it is easily done on the lathe.