Installed the new motor, pickups, brushes & a traction wheel and have 100% improvement. My Piko Transformer has 28 settings - the Loco would previously start to move on setting 20 and now starts to move on setting 14 (Steam sounds kick-in on setting 10). It also will now handle my 4 degree inclines - does not stall-out anymore. It does run a bit jerky on low settings in forward mode (14-18) but then runs smooth as I increase power. It runs completely smooth in reverse regardless of the power setting. I may tinker a bit with this later but am extremely happy with how it runs compared to before.
Really appreciate all the advice - I took dozens of pictures during the process to make sure I could get the pieces back together. I would not have attempted this project without all of your help - nice to be part of the community!