By Andrew Bluestein NEFJ Correspondent METHUEN – It was a high scoring affair in Methuen as the top two teams in the Merrimack Valley Conference squared off Friday night. In the end, it was Andover who came out with a 41-34 win over Methuen in a battle of unbeaten teams. The headline in this one was Andover senior Lincoln Beal who stole the show. Beal has been dealing with an injury,…