Hello, I just inherited two LGB engines from a family member. Specifically, 2018D and 2019S. They both look in good shape, but haven't been run in years. Here is my dilemma; I began to look at lubricating the wheels, but as I did I kept finding a light grey/green powder/grit substance falling out of the engine, when I opened up the front of the smokebox door more of the of the substance came out. Please see attached pics. What is it, and how bad of a problem is this?!? I have never worked with G scale before and I'm definitely a newbie!! Many thanks for advice and thoughts.