You have certainly taken on a difficult challenge. Folks that have assembled 904 replicas have indicated to me that there are characteristics of the car which make it very difficult to build. There are certainly books out there that have all the information you need and the author (mmikedino) of the best I have found is on this blog sight. Perhaps you can buy his book on Amazon.com.
Then there is The-Blueprints.com on the Internet. I am confident that with a little more surfing of the Internet, you can find all of the information you need. Where are you getting the fiberglass body? This is not something that one would normally do from scratch. Are you trying to exactly duplicate the original or are you willing to make some allowances for contemporary technology? After all, we have progressed a bit in automotive engneering since 1963-1964.