Great work again and seeing it does make me think that if you are going to model this sort of locomotive equipment, scale accurate fidelity to the prototype is the only way to do it. You have the advantage of having seen a prototype preserved in a museum.
I’m also grateful to be reminded of Precision Scale’s cab detail parts. I imagine that these are true O scale and so fitting them in a sub-scale interior, if that’s what 3 rail O scale models come with (as I believe to be the case) might be a challenge.
One belated question: you noted above with respect to the motorized roof fans on these engines the following-
”Hi Hancock, the rotating roof fans are a nice feature on these K-Line engines. I did not tie the power for the fans into the EER board because I was not sure how much current they drew. For my setup 18VAC goes into a small circuit board for the fans (mounted on the shell) and then DC voltage come out for the small fan motor with pulley. Instead of connecting it to the EER board I took the easy way out and connected the input for the small circuit board to the red pick up wire and the black common wire. The down side is the fans rotate anytime the track has power.”
What circuit board did you use for this purpose? I have repurposed some very small HO DC power supply boards in the past but now wonder whether they are up to the task of constant running with an 18 volt input. Finding small enough AC to DC boards is not easy, especially if they have adjustable DC output, although there are some that are built for LED strip lighting. Did you use one of these or something else?