WTB 26.0 100-110 Cinelli stem (or DA 7400)
XA, 1A. The build is 7400 Dura Ace, so that stem is fine too, but not a big budget.
Silver!
I already have a 26.4 and prefer not to shim.
Might consider another stem meeting those specifications if it isn't heavily labeled (unless it says Merckx).