[Engine] Rocker cover gasket

[crickleymal]

I'm about to change the glow plugs as I'm having difficulty starting. When I looked at them (to see how difficult it was) I noticed that there seems to be a leak from the rocker cover gasket. So I thought I might as well change that too. However...... Carparts4less (or Eurocarparts they're the same) list an upper and a lower gasket which seem to have different shapes. Are there really 2 gaskets? If not which one do I need?

http://www.carparts4less.co.uk/cp4l/c/Ci...ac0&000541

http://www.carparts4less.co.uk/cp4l/c/Ci...78d&000541

The leak (it's not a new one) appears to be just above the glowplug at the fuel filter/gearbox end of the engine.