Vintage???? You count this '929' as vintage???
It's not that sort of car or a vintage or classic version of Mazda which you are treating to restore as all originals... so the things you mentioned as Steering type & design, fender mounted side view mirrors all are well known by owner because he had been using the ride since he used to learn driving on that 929's do not think that he's a kind of kid who usually tries to jump in these sort of different projects/D.I.Y or not a new guy in Automotive field because he is a position holder Automobile Engineer and have performed in many famous Automobile companies such as TOYOTA Indus Motors, Hyundai Pakistan, Chevrolet Pakistan, Shahnawaz Pvt Ltd for Mercedes Benz, Hino Pak & currently working with Daewoo Motors.
So he knows all the things very well but all the matter is his choice, as far as colour/design of seats, door trims & dash board is concern,, i totally agree with your views that those things really does not suit but its all about choice....