I'm thinking that I'm going to pull the cable back out and cover it in clear heat shrink. The outer sheath is made from a metal coil and once well lubricated the oil can work it's way to the outside of the coils where it'll attract dirt and grime etc. So the clear heat shrink should prevent this but keep it looking original.
Learn something new everyday. I didn't know they make clear heat shrink.
I sheathed mine with black heat shrink.