I got an update from Showcase. Not as rosy as one woudl have expected. Here is what they emailed me:
These PRR Position Light Signal Heads are designed to be populated with individual 402 LEDs, sold separately on our website. The LEDs are available in many colors. They come soldered with fine 40 AWG wire for easy routing into the signal head openings and mast. Aspect black-out covers are provided as an option for covering openings in the signal head shield. Please see the detailed instructions by clicking on the instructions tab on our website. This signal head is designed to fit our PRR Mast Assembly #598. Our signal heads and mast assemblies are sold separately so you can mix and match to meet more specific demands.
So you have to roll-your-own. No circuit board with the LEDs installed, and they suggest running all 18 individual wires from the head down the mast. 2 heads will be 36 wires! So this will be a tedious manual assembly process (even if you rewire the LEDs in the head to reduce the number of wires.
