train in a row about a bottle of vodka.Darren Thomson was travelling on a train heading for Paisley Gilmour Street Station with his brother Mark Thomson and a pal when the spat over the booze broke out.Thomson, 28, grabbed his brother by the throat, slapped him on the face and punched him ten times during the violent bust-up in front of horrified passengers.The savage attack was caught on CCTV on board the train, which was travelling between Woodhall Station in Port Glasgow and Paisley on June