Have you run this loco yet ?
These were famous for having cracked drive axle gears. Replacement gears are available at Northwest Shortline.
I have rebuilt ( re-geared ) a couple of these, one being their Light Pacific loco. I also added track power pick-ups to the tender.
They are great runners when everything is fixed. The locos track better if you replace the driver axle springs with ones that are less stiff.
There is an old issue of Model Railroader with an article about how to up-grade these locos for better running.
I have about a dozen of these on my shelf to go through. As for me, I thought they were "good enough" for details. Some years back, you could find these at train shows and on e-bay for $40 to $65 as they were sold with the bad gear issue, but not so much now.
Have fun & enjoy....John