After 2.5 weeks, the lion kingdom was reasonably satisfied.  The hinge area was the most complex area.  Started it by implementing a 2D bezier function.  The complex surfaces simply weren't possible with Freecad's 1D bezier function or any combination of booleans.  These curves were manually programmed & test rendered, 20 seconds per render.  It's a shame so much time has to be spent doing what was instantaneous 30 years ago, just so modern programs can be written in Python.

After a few days of that, decided to neglect the curves in the rest of the hinge & make those sections in the GUI.  Made orthogonal sections in a scratch file & copied the manually drawn sections to a file where the scripted sections were already run.  This overcame Freecad's lockups when loading the combined grid.

The hinge still wasn't perfectly seamless like the real thing.  Many cutouts & details were left out.  Besides running out of time & planning for Elon to change the design, Freecad was burning 1/2 gig of RAM to render a single grid fin so polygon count was starting to run out.  Reviewing some Asphalt Extreme models, they too cut corners to save on polygons.  The mane problem will be texture mapping.  

It was an educational experience in how the grid fin flips out.  That part is never intuitive in the webcasts, but becomes quite clear when you model it.  Despite the lack of accuracy, the model contains a lot of details which aren't visible anywhere else simply because they have to be there for the model to work.