Having received the Showcase 3-color LED assembly a couple of days ago, I've been test-fitting the LEDs to my standing 3D artwork for old-style (GSC and US&S) vertical 3-color signals, both in visor and old UP hood style. Not that I'm avoiding the signal heads Showcase is offering, but I am, as their model is of the modern Safetrans style which would be an anachronism on my layout.
First of all, I am elated that the LED board is so thin that it easily fits within the to-scale housings. Incredible. Haven't yet discerned if the wire is #36 or #38, but in either case threading wires for two heads on a mast will not be a challenge at all as long as I stick with the Ngineering.com thin-wall stainless steel tubing.
The gotcha... there always has to be one... is the LEDs are on scale 12" centers. That's an "oops": 1:1 is on 11" centers. Since I have prototype heads in my shop, my 3D-printed models were, of course, following the prototypes. I fully understand the "modeler's assumption" that 3-color signals were on 1-foot centers as I had made that very assumption for years. So it's not quite back to the drawing board, but it sort of is.
Hopefully I'll have something to show by the weekend.