Andy - I saw your post on another forum about your machine, so I went out and got a brand-new Tekpoint out of my detecting box and examined it ... here’s what I posted. I can’t say for sure yours has been “used”, but I doubt it based on what you described and pictured.
“I just opened a brand new Tek-pulse and it is in a clear plastic bag. The bag is slid into the “holster” along with instructions. The end is folded over but not taped or closed.
As far as the end cap, it is installed as part of the assembly process and a slip by the assembler could cause the marks you have pictured. The F-point I have used for some weeks has similar but less evident marks to yours, but I have had the cap off and on a few times.”