Notice that he is referred as "CamPbell" in the "Twelve Deadly Cyns" Tour Book and in "Sisters Of Avalon" and as "Cambell" in the "Twelve Deadly Cyns" album. I don't know which spelling is the good one.
Played Violin, Mandolin on the second version of I'm Gonna Be Strong
Played Mandolin, Guitar, Violin during the Twelve Deadly Cyns Tour
Did Siturn, Violin & Guitar on Sisters Of Avalon album