I want to replace a few incandescent bulbs in my old, HO formerly-DC locomotives.  What size LEDs usually fit in these locos, and what "color" LEDs look the most realistic for the 1920s?

Thanks

I would like to use the RailCrew switch machines on my layout because of clearance issues under the layout. They use an (On) Off (On) momentary switch to operate. My knowledge of how to wire is limited. The attached diagram shows their wiring schematic with what looks to be a common or negative wire and two positive wires going to LED lights. I can't find an example anywhere on the Web as to how to wire. A picture or drawing off where each wire would go would be a really big help. I'll will be using 2 LED's to indicate direction and both have resistors attached already.

I have watched the videos. My 6 wire flat cable is hooked into the left port on the Power Panel. Adapter is plugged in to the back. Before doing this, I did check that there was the proper voltage coming out of the plug that goes into the Power Panel so the adapter is working fine. Little black plug for the wires to go to the bus line only goes into Power panel one way. I have attached two wires that are 18AWG tinned copper stranded wire.

Hello!
I was asked by a close friend to install and wire two Tortoise switch machines to operate a crossover in his layout, but I am not familiar with the wiring of those switch machines for that purpose.

To set both turnouts for their respective normal routes (i.e., to run trains parallel) or when set for a train to cross over from one track to the other, the Tortoises are supposed to be operated (manually) with a two-position toggle switch so both turnouts take their respective position with a single control. Power source is 12VDC.