Cool, good suggestion. Yeah getting into them may be tricky without leaving permanent damage. I have a spare one i may try out first.
I couldn't get into mine at all. I've done it on a Honda VTR before using translucent fluro paint meant for an RC car. That works well over white (I needed to change the needle colour as it was an import and the mph conversion sticker was white). So humbrol or similar is a good shout. If you can get in!! Mick..
Watched a program on the clock factory in America that used radioactive luminous paint. The ladies used to be told to lick the paintbrush into a fine tip. No teeth or healthy children but some fine looking clocks [emoji15]