Wilbraham here... how are you all... as for where Western MA starts I think you draw a line from the eastern shore of the Quabbin straight up and down (North to South) and start there... although that would leave places like Hardwick and parts of Ware out.... I mostly like those towns so what the heck lets keep them in... maybe the line should start just east of Sturbridge?
I would hate to give Central/Eastern MA any town I like... they already took all of my tax money and representation away from me...