Quick guide to spot the differences
Mk I - bonnet and boot hinges are externally visible on show. Enclosed 'W' on front side wings.
Mk II - concealed hinges, but from the front still retaining white rectangular side/indicator lights outside of the chrome. Small rear light cluster as with the Mk I.
Mk III - front integrated orange lens for the indicators that are circular and enclosed by a larger chrome trim extending from the grille. Larger light clusters fitted to the rear.