Any question answered...

Valve extenders.

I've got a couple of old style Vittoria tubs without removeable valve core. I plan to use these on a 80mm carbon rim therefore I need an extender or two.

Will the extenders marketed for use on removeable core tubs work on my tubs? Or should I go for another type?

Mavic do removable ones. http://www.chainreactioncycles.com/Models.aspx?ModelID=55304

Screw em in, pump up and screw em out.