I used Pongo's coin button labels on illuminated red buttons on my cab:
The photos don't do them justice, they glow a very bright red and the cut-out coin text really stands out, with a bright red ring around the button too.
The cab is a pre-built reproduction Jamma cab, but I've modified it to be a mame cab and replaced the joysticks and buttons with Magstik Pluses and gold leaf switch buttons, as well as wiring up some admin buttons and various other improvements inside. It uses my own custom Mala skin.
I also used Pongo's labels for the joystick dust washers and the admin buttons. They really finish off the machine nicely.
Here's a pic of the full machine: