Storage

i would leave all the fluids as they are... drain and replace fluids before you start driving it again.

Yea i would definitely leave all the fluids in there. Probably toss some moth balls in the interior and look for a product to keep mice out of the car! I have actually heard thats its better not to put the car up on jackstands such that the suspension unloads, i dont think its good for the springs. You could put it up on jackstands by lifting from under the axle and under each front control arm so the car is in the air but the suspension still has the weight of the car on it. Is there a way your father in law could go out there every couple weeks, hook up the battery and start it?!

Once the oil drops out of the top of the motor all the rubber/viton seals are going to dry up. Starting the motor once in a while and just letting it get up to temp for maybe 15-20 minutes would really help minimize any seal degradation. just MHO.