Beogram 4002 (5523): Replacing the Incandescent Light Bulbs of the RPM Trimmer Scales with LEDs

Today I replaced the incandescent light bulbs that illuminate the RPM trimmer adjustment scales in the Beogram 4002 (5523) that I am currently rebuilding. I installed my custom designed SMD LED assemblies. LEDs last much longer than incandescent bulbs, i.e. this is a desired upgrade if long term use of the Beogram is the goal. This shows the latest re-design of the LED boards before installation:

These assemblies are available to other enthusiasts. This video shows how to install the LED boards. The first step is to take out the trimmer panel and remove the light bulbs:

Then the LED PCBs can be implanted:

The boards are designed that the original covers still fit perfectly over them:

Then the panel can be re-installed. These two pictures show the LED boards in action. Note the red scale hands. They show up red since the LED replacements are based on red/green bi-color LEDs whose intensities are calibrated to yield incandescent lookalike light, while containing red photons that can be reflected by the red scale hands.

If single color amber LEDs are used this does not work and the hands show up grayish and only turn red if there is red-containing light present from other sources such as incandescent room lights.