From the red hair I would guess they were celtic or related to them. I remember vaguely there was a group of Celts that invaded and fought the locals, I am not positive of the timing. They may have come later. There were Celts (Cisalpine Gauls) south of the Alps, but they weren't the Etruscans. The Celtic languages are Indoeuropean; Etruscan is an isolate.
My theory is that they were like Basques (also an isolate).
They were much more interesting than Basques though.