The list was compiled from references and pictures of the Dearborn plant during the early years of Mustang production. Some of the items are references from the Allen Park facility (per Bob Fria's book).
Remember that Allen Park didn't assemble production cars that was where they showed the plants how they had figured out how to assemble - of course they took that info back with them and modified that to fit their plant, layout and specific situation
Couple comments
The inspections were an on going thing - some may have taken place at mid point but most took place on the line to correct the problem (if any) before another part got put in the way or would effect the visibility of the problem or its fix. Some of the inspectors (not the final inspectors) described being on the line with the assembly workers
Was told by a manager that the tops were handled after they got to the holding area since few cars needed this and if handled on the line it would slow up all the car
Not sure what you mean by "dash board assembly"? Think the electrical would need to be in place before you closed up the dash. and of course the main loom would have to be in.
Dearborn in 65-66 looks like the wheels were on before much of the interior parts were added
Noticed you skipped the suspension That would have to be before your "body drop" thing
Looking at some pictures the rear wheels were on before the front ones and before the front sheet metal. This would allow them to spray the front wheelwells after everything is in place but apparently they already had the rear ones in place - looking at the pictures
Looking at Dearborn pictures 65-66 looks like hood after wheels and tires possible one of the last things. Guess that would make things easier if there was engine start up issues, filling fluids and such
Looking at pictures they might have done some of the fluids at the same time as front seats
Enough for now
