Just like everyone that came before it the development of this craft started with research of the real thing, then it was right off to building, and here is the first prototype that came out
From the first prototype it was time to add crucial features like a launch escape system
From there it was time to add the launch infrastructure like the crew access tower and launch hold down mounts
And now the Saturn V was ready to go, but please note that there were some other undocumented changes or some statistical changes like fuel balance and thrust levels as well as ascent trajectory changes through multiple mission simulations. Now here is a side by side of mine and the real one