I have made some ropeknurl wheels and a siple tool to a friend that build cane rods. I'm sure they are available, but this guy wanted somewhat special size/pattern.
I have build some knurl tools, but completely hashed up my clamp type one...I tought I was clever and rushed it but instead I learned something: I's easy to have a bright idea - implementing it is another matter.
Knurler is nice when it does the job!
Pekka