Ken, I'm afraid this whole thing is so riddled with unwarranted assumptions, mechanical and practical impossibilities it is turning into a bit of a joke.
Leaving aside the miraculously intact arrival you're going to remove some electrical components that have been buried in seawater and sand and attach them to a home made steam turbine.
Might I suggest a little research on a) steam turbines and b) boilers?
Using the Apu as a turbine is vanishingly unlikely to work due to the vast amount of workshop modifications needed to even get steam into it - ie removing the compressor section off a single shaft design and revealing the casings(!) plumbing the steam feed and controls ( oh yes, aircraft battery and seat springs for welding rod...) and then finding out the hard way that you'd need a boiler the size of a locomotive to produce the required amount of steam (apu probably produces several hundred KW total output, go figure your boiler size at 60gal per KW, not to mention the fuel consumption) were you planning to dig an oil well too?
Anyway, steam turbine design is very complex and extremely sensitive to anything less than ideal, they only run in a very narrow range of design speed, steam pressure and temp. There is not a chance in a million the apu would do this. It might turn but it wouldn't produce any power. Plus the lumpy saturated steam your home brew boiler would produce (50 psi? Come on! Try four to eight times that to run a turbine) would likely smash it up in no time. If by a miracle it did run efficiently it would probably over speed and self destruct without a complex governor. This is pie in the sky!
Go look at boiler design. To get the energy out of fuel requires miles and miles of fine tubing all perfectly welded with welding rods, not seat springs, it isn't just a big kettle, hydraulic tanks simply wouldn't work.
use the air starter as a turbine? Better chance than the Apu for sure but again, where are the cast quantities of steam to come from? Not continuously rated, same problems with expecting a machine designed to work on air at one T & P to work with steam at another energy level.
It's just far too far-fetched and based on boys own enthusiasm and lack of any technical thinking. Sorry, it's like that guy in the Nairobi slum who built an "aeroplane". You can't Just make up high tech engineering without any training as you go along, trying to do that with something as crude and basic as a small aeroplane was self evidently doomed to ignominious failure. Trying the same with bodged gas turbines and a kettle is orders of magnitude more ambitious and with the greatest of respect you've demonstrated a number of times your complete lack of knowledge in both engineering and physics. This is too technical a subject to be tackled in this way without it descending into pure farce.
I think some of the suggestions you've been getting here are akin to bystanders chucking food over the cliff to encourage the Lemings...