All the machines I’ve had past and present had accommodations for coin tray lights.
Never had one that was wired to a relay/switch.
They just come on with the rest of the lights when the machine is powered up.
Part of a restoration would be to clean the plastic lenses and bulbs.
An outrages amount of tar and nicotine on the lens indicates a few of things.
Previous onwer(s) smoked, wasn’t professionally restored, or its original from a casino.
Machines covers with tar and nicotine take a little longer to clean. But it’s a good indication that the machine is in its original state and will clean up really well in my opinion based on past experience.
One cautionary note, be real careful when cleaning the interior side of display glass.
Its best to test a small area. Sometimes just plain soap and water will remove graphics.