If you won't drive it, there's no practical way to get the oil to operating temperature. I say don't bother starting it at all.

I imagine coolant is better than no coolant and fresh coolant is better than old coolant. I'd do a full descaling with citric acid and deoiling with dishwashing soap before filling with fresh coolant.

Will you store it indoors? On pavement? In a damp field? Those conditions will determine what other precautions to consider.

And rodent proof it! I suppose that depends on what rodents you have where you are. Make sure all the passages through the forward and aft bulkheads into the cabin are sealed. I don't know how to protect the hood pad and engine bay wiring harness.

Sixto
87 300D