Beautiful pipe! Ever tried using a clean pipe cleaner laid out horizontally to clean/buff that crease?
This guy also made a couple of videos worth watching... :D
https://www.youtube.com/watch?v=eI8uDWs2szY
https://www.youtube.com/watch?time_continue=1&v=yEbDiKfeqdw
I wrap paper around a small, flat needle file to get the crease oxidation removed. Just be sure to angle slightly towards the crease, as to not put in another crease..