Instead of reposting the rear light setup it can be seen on page 12 of this thread in post #226 where I addressed the faded lens of the left rear parking light.
Below are pictures of the rear light/number plate assembly on my work table and other pics detailing the light in question.

An overview of the rear light/number plare assembly

My failed LED alteration is seen here. the LED wires are soldered to the bulb elements. In this way no alteration was need to the original bulb holder.

Here I have place the normal incandescent bulb in its holder and you can see there is no reflector behind any of the lights:o
Now the next step will be to alter the Honda CD70 brake light reflector to fit nicely in the space behind the brake light bulb 