Man, I just got a set of Silver Foxes and has some of these same questions. Thanks for bringing them up.
My tail weight, the tee looking weight that goes at the end, wasn't glued on to anything on any of my Foxes. In fact, it fell off into the bag on my standard and I didn't realize it was supposed to be there at first. I hadn't noticed any kind of inner sleeve and I think it may in fact be missing on my standard as the spine is measurabley shorter than on my UL and vented. Mick, do you think you could take a picture of the bottom of the spine so I could see the end of the main tube, the inner tube and the tee? Also, did you put that colored tape on the weight? (EDIT: Yes, I see you mention electrical tape up above.)
Cheers,
Dan