I purchased this loco used in, I think 2001. The Key version was released in 1985 so I was a bit skeptical, however the tire treads did not look worn, so I took a chance. It ran very well as analog DC.
However, I could not leave well enough alone and had to add DCC. The thing had a short that I could not find and only in the past year found it.
Here is the stripped down original loco............
I found the short to be in the plates that clamp around the two gear towers and the fact that a small insulator was missing........................................
I used nylon screws in place of the original metal ones and no more short. I replaced the brass tender with an Athearn plastic one a few years ago. I have re-worked the pickups, added an ESU 73100 decoder, and a 9x16 speaker. Similar to my Big Boy install. I added headlight only to aux 3 pad. Works well, runs well, sounds good. All is fine , for now.........................
Yes, all that fits under the tender shell, well almost. I did "open up" the square hole under the coal load to gain a tad bit of headroom. I will try a video in a few days and post, if this is of interest.
Thanks for looking and as always, have fun,
Carl