Thinking about any scraping from the shaft, I decided to to order a new muzzle. The Hammerhead (
Home of HammerHead Spearguns) it will bring the bands inline with the shaft and maybe help? I don't have any issue witht he HF muzzle, but I like to try new things. I did make my HF open and added a weight to compensate for it and it's still balanced well. I got one for my Cayman Cave 55cm too.
On my HF I don't think I have much wear showing on the track area. Mine was more knicks up near the muzzle from the metal wishbone that I noticed. I'll have to look at the track again, maybe I just did not pay attention.
I've also wondered about a teflon strip across the top.