I have a pair of them but they aren't numbered sequentially. One thing I've noticed is that one of them has a taper from the bottom (where it joins the barrel) to the top of the front sight, the other has straight sides all the way up.
I was told this is because Milleniums start out their lives to be Cattlemen ubtil there is something that excludes them, then they're "bumped" down to the Millenium line. The way it was explained to me it sound as though Milleniums are effectively "seconds".
They still shoot great. The first one I bought, after a good cloeaning & about 500 rounds through it has a 2.5 pound (crisp) trigger pull, the other has a 3.5 pound pull. That's pretty fair for a stock gun! My gunsmith tells me that with an action job, they'd be better than what the original cowboys had.
I took my backstraps to the buffer (& the Dremel tool) & polished up the brass & also took off all the sharp edges. I also had to do a little fitting on the grips on both guns to get them the way I wanted.
All in all, I'm impressed, I'm proud to carry my Ubertis.
BTW - I found my Milleniums at the local Gander Mountain for 279.00, and was able to carry them home after the waiting period. Cabela's charges S&H, plus a transfer fee at your local gun dealer (Gander mountain charges $25.00 & they're on the cheap end). My advice would be try & find them locally (and order your accessories from Cabella's with the money you save)
Take Care,