Action Comic Wasn't the 13th Floor in another Fleetway comic called Scream? In the mid 80s? I could be wrong.
Lights Alive It didn't have LEDs in it! Each "pixel" was a little bubble of very thin plastic. Pushing into the pixel with the tools, pushed the plastic down to allow light through.
The bubbles were faintly tinted, and for some reason in their unpushed state, didn't allow light through.
To reset, you'd push the whole screen upwards, and an internal roller covered in little blunt spikes popped all the bubbles back out into their opaque state again.
The tool had a single pixel pricker on one side, and a wheel on the other for drawing lines. I vaguely remember shapes you could press down too.
For a replacement lightbulb, take it to a shop that still sells torch bulbs. Did it take 3 batteries? 3 x 1.5v = 4.5v so you're after a bulb for just under or over that voltage, the same fit as the old one.
Torch bulbs are getting pretty much extinct, maybe in the future somebody'll solder in a white LED. Problem solved!