Managed to Torque up the cam sprocket without having to take of the alternator cover off to get at the rotor bolt.
I found that if the top bolt was just to the left of being at the top you can Torque it up as the tightening action holds against the sporocket rotating - at the top it rotates down clockwise, too far on the left & it rotates anticlockwise.
Looking at the manual there are 6 Copper washers on some of the cam cover bolts - just wondered why this is if anyone knows ?