Just to add my 2 cents, climb underneath and crack the drain plugs for the engine and transmission. Open them SLOWLY until liquid starts to seep out, and place a pan under them. There will likely be some water in there from condensation inside the cases. Let it drain until you get oil.
I bought a 70 that was stored inside once that had almost a gallon of water in the transmission case, and had been sitting for a few years in a barn. They sweat bad on the inside from humidity.