I am new to building, but have done some decent first off poles. Upon inspection of one of my poles my Cousin pulled out this old ugly stik in sad shape. Since he stilled used this pole and claimed it was a sentimental favourite I offered to re-furburish it. Well then my obsession with this craft took over and I began stripping it down to just the blank. I was determined to give him back a new pole. Off went the guides, no problem but when it came to the grips and real seat I discovered something new to me, again I am new myself so thats not a surprise. Anyway under the EVA grips and real seat was a piece of Aluminum pipe, approx. .600" o/d. It seems the pipe replaces what I expect would be rod blank. The blank has a plastic adaptor piece that is bonded into the inside diameter of this pipe. The pipe then extends the blank another 11 inches for which your grips and real seats have been bonded.
I don't know what I am asking here, I guess I would just like to know how common this is, and if anyone else has come across it. At first glance I figured it wqas just the signature of a lower end stik, but again I would love to here opinions on what this in effect does to the build of the rod.

Thanks for the opinions
Steve