First I took a pic with a straightedge for scaling:

You can see all the scratches.
I then imported the pic into my CAD program and traced over the outline which produced this:

I then printed it off onto adhesive-backed paper and stuck that on to some adhesive-backed thin black plastic sheet that we use at work. This plastic is about 0.75mm thick, has a matte finish, is very tough and has a great adhesive. It's then off to the cutting board with a decent scalpel or hobby knife. Cut along the printed outline. Takes about 10 minutes and the more care you take, the better the end result:

I finished off the edges, removing any dags with P180 sandpaper - gently! Then clean the clamp with spirits of some kind - petrol, turps, metho, vodka - whatever you have lying around and let it flash off.
Remove the adhesive cover backing from the plastic and offer it up to the clamp. You only get one go at this, so make sure you get it lined up ok. Peel off the printed label and voila!

What an improvement.
I've got another 2 already stuck down, all it needs is the ten minutes of your time with the scalpel. I'll post them to the first 2 that want them - just PM me your mailing details. If anyone wants the CAD model in DXF or DWG, just let me know and I'll email to you.
edit: deleted reference to free TCAD.

