The old ones can be removed if you're careful, I've done it before. I used a razor blade to get underneath it and it was going so good I quit being so careful so I cut through it a little bit. Its still usable but it will look like there's a small scratch on it. It's in good enough shape that someone could probably scan it and print it on aluminum plates, an option I'm checking into, but I would rather just buy one. If I find someone who can print one I'll get more than one made.
I need one for my K5.
I remember running across someone who was screening these onto new aluminum plaques, a while back. I'll dig through my old links to see if I can find it.
The K5 plate is very different, its got the frame number stamped on it. If you can find that source that would be great.