Re: What to expect
I think the carpet is snap in and can be taken out, cleaned and possibly be ok, the very first thing I would do is to get that motor and outdrive drained, take the plugs out and spray mystery oil in each of the cylinders liberally, and hook a breaker bar to the crank shaft and turn the motor over a couple of dozen times spray mystery oil in a couple times during the process, drain the fuel cell completely, and replace the starter, fuel pump, alternator, power steering and trim pump, buy three or four fuel water separators and oil filters, cap rotor and wires.
When I say drain I mean everything, every once of fluid in the oil pan and fuel cell, get some cheap oil and run it down the motor to flush any remaining water out, go over every electrical connection and clean them, I would solder them, the gauges should be Faria which has a pretty incredible warranty so you may as well test it and see if they can be gone through otherwise get on ebay there are plenty of Faria gauge sets there.
Cycle and re lube your throttle and steering hopefully its salvageable.
After you have let the mystery oil settle into your motor and your fairly certain your electrical system is ok and your throttle works, grab a LARGE fire extinguisher and hook the hose up to the outdrive, install your battery, plugs and a fresh fuel water separator and oil filter, a couple gallons of fresh fuel and cheap oil and fire her up, be prepared for the exhaust to smoke quite a bit its the mystery oil.
Best case scenario is that the motor is ok but likely got kicked in the junk, if it runs(no knocks) go ahead and let it run the fuel dry, change the fuel water separator, oil/oil filter and plugs put some more gas in and do it again, things should run better with less smoke and it may be ok.
I would look into a rebuilt outdrive, not sure your going to need it but you may as well have the info, your also going to need a new blower.
I have to tell you your pictures make me sick to my stomach, best of luck to you.