Saw these on Thingiverse and thought I would share.
Left and right wheel spinners for Honda 125 wheels. The author states they 'might' work for CT90 wheels. I guess anything can be made to work with a little ingenuity. There are also some for the pit bike wheel floating around.
https://www.thingiverse.com/thing:5869231
For those who don't know what 'Thingiverse' is, it is a repository of 3D printable models. So If you want some and you haven't the foggiest idea about 3D printing, you might want to try and befriend a local tech-geek.
The original source of this info was on the GB Cyclekarts group -
https://www.facebook.com/photo.php?fbid=7408313915886721