I feel the answer to this question won’t be answered flatly by just one person here so I will answer and tell you what I’m doing and where I’m going with mine. I am blessed with an awesome better half that likes to go to off the wall places and she doesn’t mind what I spend on my car. The car in question was something that was borderline on being a parts car or a real ambitious project. I am focused on mainly making my car a reliable, roadworthy driver using the best parts I’ve collected. Mine has a very nice driver quality interior. It has rust in the floors and in the frame, has old body repairs that are ugly but is nowhere near to the point of throwing out. Authenticity means absolutely nothing to me concerning this car so I’m going to use the best aftermarket parts I can find. If your car isn’t like mine then by all means buy the authenticity manual and fix it correctly. It should pay off.