75 Duster Neutral Safety Switch... I need to replace it!

Hey yall never told me that tranny fluid was going to leak everywhere!!! Now that I made a huge mess of my parking lot and got some kitty litter to soak up the spill... I replaced the NSS.

While under the car I found the reason for the tranny leak. It is a corroded cable right near the tranny pan. Any idea of what this is and how hard it is to replace?

Also, after the replacement of the NSS and of course tranny fluid, We tried starting her up... everything was fine at first but once she was turned off and we tried to restart... nothing! She still needs some kind of spark to get her going (i.e. turning the headlights on and off, putting the car into gear and back into park a couple times). It is really frustrating that I spent money on a part that didn't need replaced just because a mechanic told me to. Any ideas on how to REALLY fix this problem??? Thanks in advance!