The tyres have a 5 year life ( warranty wise) if kept in the dark they will last longer. Mine are 8 years old and are still soft and no cracks on the tread blocks. There's a debate regarding suspending the car on stands to save the suspension and tyres. I reckon it wouldn't hurt. Fluids should be OK as long as you replace them on recommissioning. Fuel -- gone. In the old days
oil in the engine would actually damage bushes, cam bearings and big ends etc due to high sulphur content; not now. Remove (secretly) a vital ignition bit to prevent unauthorised use and finally cover it up.
The hardest part is leaving this machine just as it's ready to go. That's tough.
Good luck with future business !
Regards Smithy,
P.S. I might have mine finished by the time you get back !