About the only reason that I still run Windows at home is so that I can run the Microsoft Flight Simulator. I have FS 2000 (FS2K) and FS 2004 - Century of Flight (FS2K4 or CoF). I asked for CoF because I really wanted to fly the Spirit of Saint Louis in simulation. I read the book. I flew the flight. Now I have flown the flight again. I tried to take better notes this time. I also took some screen captures .
The 3 Spirit of Saint Louis flights are laid out and described in fairly well in the CoF "Select a Flight" panel. This panel lists the historical flights that are available and a few commercial style flights that utilize historic aircraft. It also has a section where you can select flights which you have created and saved with the "Create a Flight" panel.
For each flight, a background document is presented and a flight briefing. In the case of the New York to Paris flight (NY-P), there is a reasonably detailed flight plan. More about that later.
Selecting a flight puts you at a modern airport located where the flight originated. There is no flight plan in the MS FS sense so there is no navigation log nor any way to do fuel planning. So the first thing that you should do for each of three legs is to use the MS FS Flight Planner function to create a flight plan. To make it more realistic (for me anyway), I selected a grass strip near where the the flight began. The notes for the NY-P flight actually note that the airport is no longer there and that they use a close by modern airport. In fact Roosevelt Field is now a shopping mall.
In laying out the flight plan, select the beginning and ending airports and use the Direct selection. This will plot a great circle course. Then look for intermediate airports, VOR's, NDB's, or intersections which fall on the line or close to it. Select points about an hour apart for convenience. This works pretty well except for the middle of the Atlantic. Between Cape Breton Island and Ireland, there is nothing for about 14 hours.
The Lindbergh's book Spirit of Saint Louis does not say much about the trip from San Diego to Saint Louis. There are obviously some mountains to get over. The great circle route required at least 8000 feet of altitude and this at night. I had trouble getting the plane to go that high. Do not attempt the San Diego-St.Louis leg with a full fuel load. It is not necessary and will make flying high impossible. I found the reference that the fuel was only slightly over half full. But there is the additional payload of a suitcase with business clothes. In re-reading, I see that Lindbergh made 13,000 feet to clear the peaks at the Contental Divide
The earth inductor compass was not working at San Diego. The bearing on the rotor was frozen. This is not noted in the pre-flight notes and I forgot about it so I flew with the EIC. Try flying it with only the wet compass.