Fill the gas tank, air the tires, maybe disconnect battery...Done
Where is this car stored? seems like the location you picked has moisture issue and not only developed the mold it also rusted moving parts.
That's what I was thinking! My in-laws used to have an early 2000's Monte Carlo that had leaky door/sunroof seals (water got in at every rain shower); it sat uncovered/not driven for 3 or 4 years and didn't have anywhere near that amount of mold inside it.It sounds like he picked the ocean floor!