Hi, I just want to share a thought came into my mind while I reading this...
It makes me think it is possible the last verses contain double meaning and saying here about Mark as "skydiver"
"When I need to take a break from the "brushes and the knife" (think of a guitar hidden here - "six blade knife")
"And I always took a fancy to the ones heading straight into the teeth of the guns"
("took a fancy to" as to Lucian Freud from this song or as to others from many of his songs).
Regards