The Three Investigators Lamp - Three ???

Even after more than 40 years, I am a fan of the series.

About the print files:
The print profile only includes the front.
However, all files are available.
The white '?' is specified at 0.8 mm because it would glow too brightly at 0.6 mm (like the blue and red elements).
The back consists of two top and bottom layers, 25% infill, and three walls.
The .stl files may still need to be rotated on the print bed in the slicer.

Regarding the electronics I got from Amazon:
5V COB LED strip

USB socket for power supply 

USB cable with switch

Not absolutely necessary but practical, the silver tape

If the LED strips are installed in the quantity I have, a 1A power supply will suffice.
If you use a different quantity, calculate the actual power consumption or check it with a meter.