Protecting "contact" areas on brass

[Green_Elite_Cab]

Well, it looks like this was the case. While adding additional power pick ups (itself a frustrating, but seemingly successful project), i just took some scotch tape and wrapped it around the frame where the trucks appeared to be rubbing. No shorts. I hesitated to file away a part of my locomotive, but i'm sure the tape won't last forever. I'll probably remove it the next time i have to take the locomotive apart (probably for lighting and such).

I was hoping there would be more of like a covering or something i could apply to the frame, that wouldn't "rub away" so easy. i wonder if putting gloss cote on the upper surfaces of the offending brake cylinders would let it slide rather than rub. i don't think it would be noticeable there.