Briansilvermustang's last photo of the Industrial Switcher, with the nuts showing, was my initial inspiration for making changes to these. I add window material made from the plastic of gallon milk jugs. I made a paper template, then make the windows long enough to cover two sides with a corner fold. This helps keep the window "glazing" in place.
With the included circuit board inside, there's not much room inside these. Then I accidentally fried the board of one that I was working on. Which got me to thinking, "If I ran these on DC current, I could still have forward and reverse, and then free up some space inside the engine to add some weights." Which was then also my inspiration for have the option of running the layout on either AC or DC current: albeit rectified DC current. I know some folks just wire in a rectifier to the motor, running these forward only. But what use is a switcher that cannot be backed up?
Though I may have posted these on the SWAT before, here's a couple of my redone Industrial Switchers. I have others repainted to CSX, Jersey Central, another Lehigh Valley, Reading and Norfolk Southern.
It's the same Mabuchi motor in these engines that is used in the starter set die cast steam engines... so that gives you an idea of how much weight can be safely added to these very light weight locos. With the added weight, I can remove the traction tire, which helps greatly with momentary stalling when running slowly on switch tracks.
One thing I know I never mentioned, is I used to remove the lockout switch and cover over the holes before repainting. With the LV switcher below, I decided to keep the included lock out switch on the back side of the cab, rewired as a shut off switch. So I can flip that button, and have the engine in a neutral position with the lights still on, but not moving. Which is a useful option to have.