I always follow the manufacturer's recommendations. I use LaBelle light oil on the rollers, and have been doing so for years. No issues that I can tell of.
I too go to Eastside Trains as my local hobby shop. Great store, and they're certified Lionel and MTH service techs. They always let me run my engines before taking them home. And, they never call my wife to let me know that a pre-order is in!
Oh yah, great looking engine.
Alan