what year 240 is it? S14s have different electrical locations than S13s.
goto
http://www.240sx.org/links/ins...p.htm for info on the S14 swap. Check the link in my sig for info on S13 swaps.
The neutral/safety switch on the S13s is located under the passenger side fusebox. It's easily noticable because it has two thick wires coming out of it. One black, one white. Jumper that plug and you'll bypass the neutral/safety switch. Just don't have it in gear and the clutch engaged when you start the car.
As for the ignition key capture system, there's a fuse in the passenger side box that runs power to the lock mechanism on the column. As long as the shift lock fuse is fine, you should be able to get your key out. I shorted that fuse out once, and couldn't get my key out. Took me forever to realize what I had done.