Anyone know where I can buy a Katana shift knob?

I know you can get training bokken with wrapped handles for something like $15 on Amazon, and I also know I could buy the adapter for my shifter. I do not, however, have faith in my ability to mate the two in a way that would work.

I've also scoured the web looking for one, but it looks like most people opted to make their own, and it doesn't appear that anyone is selling them. Maybe I missed something.

(Also, yes, I know that some of you...maybe even most of you...would find this sort of thing gaudy and/or impractical, but I'm past all that. It's no less practical than those dildo shifters, and I think it's a helluva lot less gaudy...I think they're pretty cool).

Thanks guys.