Gil, Mop n Glow was used at the railroad shop to keep brass from tarnishing, like on steam locomotive bells that were polished to give to libraries and such of towns on the line. Why Mop n Glow? I don't know but it works. I have brass builders plates that I coated 40 years ago that have not tarnished. Same for cast iron and steel. They used it in the air brake department. For a model steam engine, just wipe it on with a cloth or use a small brush, or a Q-tip to get the product where it is needed. Mop n Glow is available in the floor wax section of the grocery store or from Amazon.