Had a search around, all engine paint jobs seem to be whole resprays. I'm only looking for a touch-up. Previous owner had a low-speed laydown so I have a very light surface graze (about the size of a oval 5-10c piece) on the clutch housing cover. I want to touch this up with some black engine enamel so it's not a bright silver patch in the nice black paint of the engine. What's the proper procedure for doing this to avoid rust, problems, etc. I was thinking of getting a very very fine file and just smoothing off the graze (carefully of course). Then get it with a cleaner to ensure there's no dirt/grease/particles. (I have normal car wash concentrate and kero currently... and a clean tooth brush) Then getting some cleverly placed masking tape around the area to avoid spraying the paint everywhere. Is there anything else I should be looking at? This feels very much like a one-shot deal so I don't want to do something I could have easily avoided.