Like has already been said above, fitting Mk1 doors will require replacing the door aperture frame and step, the b post, modifying or changing the quarter panel, fitting Mk1 inner and outer A panels not to mention all of the modifications to the shell to get these panels to fit nicely.
Then there is the headache of modifying the rear panel to take the smaller rear window, modifying the front panel to have the curved ends on the apron and a whole load of other bits and bobs.
Most people fit the mk1 rear light conversion panels, boot lid, remove the lip from the front ofthe existing bonet, stick on some 10s and a wavy grille and perhhaps overiders on hte bumpers and leave it at that. You will never get an authentic look without MAJOR surgery and as alot of the parts you need for the conversion are not available to buy, it would mean cutting them from a mk1
Look forward to seeing what you decide on.