One of the real important documents is the factory Kardex. The Kardex is not a build sheet, but it is the next best thing. The factory used these to document warranty work. Their primary use today is that they fairly well document how the car left the factory. They are not always accurate- particularily in that things can be omitted. As for Miss April, a copy of the Kardex is shown below. I typed in translations and I also blocked out the key code for the ignition. ALL items on the car exactly match entries on the Kardex!
Showing some documents below. The clear cover for the owners manual is somewhat rare and hard to find. The best thing below is the large stack of receipts. They date back to 1975 with receipts from the second owner- Wellington Love. I have contacted Wellington and we had a great conversation about the car! Wonderful guy! If you look carefully, there are receipts from the famous Porsche repair shop Lukes and Shoreman. They did a complete engine rebuild on Miss April at 171,482. Mileage today (October 2017) is 175,134.