When Euro-fever races through the national capillaries, it produces a number of side effects. One of them is various protagonists raising the question of which great talismanic figure from the past would vote to leave and which to remain in the European Union if they still bestrode our green and troubled land? Mrs Thatcher and Sir Winston Churchill have been on the receiving end of such speculations in the past few weeks.But the former Prime Minister on my mind has been Harold Wilson, the centenary of whose birth in Huddersfield in 1916 we shall reach on 11 March.For Wilson it was who steered a riven Labour Party and a divided Cabinet through the European shoals in the spring and early summer of 1975 to a referendum. It produced a 67 per cent to 33 per cent vote for staying in what was th