Rydenfan - The 9.5 Vibergs I'm selling are on the 2030 last. They are half a size too small. In fact my left foot is half a size bigger than my right (10.5vs10), so they're really a size too small for my left foot, but with a bit of stretching a 10 in 2030 would fit me fine.
My 110s are size 10. Fit like a glove from day 1, my left foot is definitely filling the boot lengthwise, maybe a tad much, but absolutely no discomfort.
Dino19 - I have narrow feet (as a size 10.5 Viberg my left foot is still only 10.8cm in width).
The 2030 fit lovely, the 110 are roomier but a beautiful fit too; no slippage at all.
To summarise: I would take the same size in both 2030 and 110. The 2030 are longer, but the 110 are wider. If you're comfortable in a particular size on one of the lasts, choose the same size for the other last, you should be fine.*
*disclaimer - no two feet (even on the same person) are alike, so take this for what it's worth.