why the voynich ist celtic

[ReneZ]

There are just some very few details which show motives with an "Italian" relation, the notorious "swallow-tails" in 3 or 4 spots of whole manuscript.

You are actually right that Italian influences, if we skip these merlons, aren't that strong.

"If we skip the 3 or 4 Italian influences that I am aware of, then there aren't any left".... 

But there are many more, noted by people who deal with medieval manuscripts in a professional capacity. Not just tiny details in the drawings.

Let's see some of this:

some hints to slavic/eastern european influences are even better