Here is mine as it stands now.
Replaced the tender with a USRA Short.
Replaced the headlight LED with a pure white one.
Installed a DN135 decoder in place of the factory light board/decoder.
Opened up the roof hatch.
Installed working McHenry coupler on the front.
I still need to replace the dummy Bachmann coupler on the tender, decide on the best number for the loco, and weather it.
After fine tuning the mechanism this little thing will crawl a tie at a time and runs dead smooth. No hitch, no hunting. As much as a pain it was to find the little things that were wrong in the assembly, the result is and incredible little loco.
For those of you finding a clicking, I found and solved one in mine after handling it repeatedly when I was working on it. Make sure the cross head guides are angled outward, away from the cylinders slighlty. Even better if the bottom guide sets out a touch farther than the upper guide. The Crosshead was hitting on the verticle link attached to it and causing the click. Tweaking the cross head guides cured the sound and click. Also cured the minor hitch so I think that may be the issue for many people out there.