Besides the parts in the picture below, there is also a written description with 2 images describing the building process. The LED is bi-color, red and green.
Hole for wires 6mm from top (.25")


Pieces primed with PS Zinc Chrome and PS light gray undercoat

LED soldered and LED leads cut off,as short as possible

Ladder is to have the top 3-4 rungs removed:

The base is to be attached so that the target is 16-17 scale feet up, (60mm)

time to add some more paint and then insert the LED and wires and last but not least glue the finial in place.
I used Humbrol 11 (silver) and 33 (Matt black).

Done.
It took me about 1.5 hours to complete the assembly.
In conclusion I must say that they are well worth the $10.
Signals are here powered with a 9v battery with a 330 Ohm resistor in series.

Here is a compiled list of (some of) the items I've used when assembling track
| Manufacturer | Number | Description |
|---|---|---|
| Oregonrail | 125 | Single Searchligh |
| Polly Scale | Zinc Chrome | |
| Polly Scale | Light gray undercoat | |
| Humbrol | 11 | Silver |
| Humbrol | 33 | Matt Black |