Rolling chassis donor for exmod n/a 110.

Evening,
I'm considering purchasing a rolling chassis disco donor, complete with engine gearbox and ancilliaries for my 110.
I've read up on the posts about the conversion, fascinating stuff, a couple of questions though...
How do I find out what gear box is attached to the discos engine? Do I need to?
Was hoping to take the whole drive train out and just chuck it straight in! I'm a better keeping the original gearbox?
I'm assuming I can also utilise the power steering box for my non power steering 110.
That's almost the main thing actually, slightly takes priority over noise, lack of power etc, is being able to manoeuvre without slipping a disc AGAIN!! Paranoid about the rickety back after weeks off work last summer.
The 110 is a fantastic base, no rot whatsoever, newish canvas hood, wolf wheels etc etc, I'll add photos soon. Could do with a fresh lick of paint. And new seats.

As a new owner of an ex-mod 110, I'll be watching this thread closely.

Got to say, at first I thought the non power steering would be really hard work but I found I got used to it very quickly and I think I'll probably just stick with it - less to go wrong. I think it's just a question of getting used to it. It can be a pain for parking though.

Oh, meant to say, what pressures are you running in your tyres? I would imagine it would make a huge difference. Mine are something insane like 55 psi. Tyre wall should have safe maximum pressures on it.

Cheers I'll check the tyres they could be down a bit, but either way the thought of power steering is nice!