As the side windows on a stock Model Power E7A shell are recessed I continued with recessed windows in the motor compartment. I used .02" thick clear Styrene sheet to cover the window openings.
I went with a couple of small dabs of Goop to hold the windows in place. If needed they can be removed.
I mounted two 2 pin micro connectors to the chassis for the headlights to connect. One connector is powered direct from the rails for directional lighting the other is connected to a full wave bridge rectifier for non directional headlights, on all the time.
This is one of four identical Model Power E7As. The air horns are a press-fit into the shell without glue, to prevent breaking them off during maintenance I remove the air horns.
I'm still working on perfecting my home-brew MARS light for all of my DC mode locomotives. I'm using multiple 5mm white LEDs to obtain a oscillating look driven with an LM555 timer chip. When I finish my MARS light I'll do a post with the circuit and a video showing it in operation.