Sporminore is in a valley in Trentino known as the "Val di Non". The Non refers to a Celtic tribe that lived in this valley and is called "Anauni" by the Romans. The Romans occupied Trent and traded with the Anauni. To this day the people refer to themselves as Anauni or, in Italian, as "Nonese". So as far as I can see the people living there today are descendants of the Celtic Anauni. And it seems likely that the Stefani family, there in 1563 and with no indication they came from elsewhere, are as well.
This leads me to red hair. The Celts are known for having red hair, most notably in Ireland. My mother's twin brother had a son born with bright red hair. My grandmother, Edith Stefani daughter of Frank, said that she had had a brother with bright red hair but he died young. When my sister and I were in Sporminore in May 2016, we met a young boy of the Stefani family with bright red hair. These Stefanis are our distant cousins but they also descend from Bartolomeo of 1565. My conclusion? We are Celts from the Tyrol!