When I was trying to fix a issue with a new purple Fluxo XL, decided to clean the internals from an old clear tube Fluxo Xl modded with a syringe I had spaced in the drawer...tried the fit in Purple tube and seemed to fit just fine... did not go further since the new internal was the focus of things.
By eye they look the same dimensionally, the wicks are different, the old ones have a larger/longer shrink tubing deals @ cup/base/stem....should work I think, but did not test drive though. Did not think to see if the new tube might fit on a pre-cut metal ce2, if it does suspect won't many repeats...though won't try that till I have a couple Fluxo Deluxe internals fail, as the first one is slated for the 13 or so unopened old clear tube xl's tucked away.
If one should manage to get a metal tube off the connector base, is possible the very tight press fit might alter the od of the base at the knurls...is soft metal, so could be some side ways expansion into teeny valleys, from the compression force of the tube forced on to it, decreasing the od, some shaving of the knurl ridges perhaps thus affecting fit in the new plastic tubes if one manages to get the metal tube off anyway. Dang things seem almost as snug as the brass collars heated to 800 F in a draw furnace, slipped on the shoulders of Ford New Holland Axle shafts deep frozen in dry ice lol, and only got one shot per unit (worked a lot of years in Heat Treating)