Mercruiser 470 underwater

So I had my dad's old bass boat in the water for the weekend and came outside to see it sitting on it's side underwater. It might have been underwater for about two hours. This boat is at a lake 4 1/2 hours from my house and there is a mech here that charges $85 an hour to repair boats. this is a $2000 boat that I have already spent $3000 to get running. All I have done so far was get it out of the water and drained. How much am I looking at to get this thing running again and is there anything I should do tomorrow morning before I leave it for a month? I am thinking of pulling the plugs and fogging it as well as spraying the electrical connections with WD 40. I have never submerged an IO before and I am worried how much effort I should even put into it keeping in mind it is my dad's old boat. Thanks in advance.

Get it running and get it hot.

depending on how deep it went and how much corrosion you get:
remove the outdrive to grease and remove the water from the bellows starter, charging system, wiring harness, steering cable power steering pump, battery cables, trim pump res,water in the hull, waterlogged foam,
trapped water in the hull

Ditto getting the engine running and up to temperature, followed by several oil changes, and repeat bring it up to operating temperature.

Pull the drive as to access the bellows area and to dry this area out.