1959 Other Ford Models Neutral Safety Switch

I'm not exactly sure how your neutral switch is wired, but it should produce a ground when in park or neutral. You mentioned a 4 post ignition switch. I am assuming that this is the switch and not a relay or solenoid. I will try to make this as clear as possible, but if you need a wire schematic, I can get you one. I use to work on older motor homes and your set-up is very similar to how ours were wired. Your ignition switch has 4 posts--1 for power, 1 for accesories, 1 for the run position, and one for crank position. You need to identify the post for crank position. You will not be able to accomplish the task without a relay or solenoid. You will need a 4 post high current solenoid (relay). It will have two large lugs and two small lugs. If your starter does not have it's own solenoid (single post starter), you will need to run battery power high current cable to one of the large lugs. The other large lug will then run a high current cable to the starter. This will leave the two small lugs. One will be the power from your ignition switch in the crank position. The other will be the ground from the neutral safety switch. It should be able to be done like this. If you have any questions or need a schematic, let me know. You can post here (preferable) but you can also PM me. I'll be glad to answer any other questions you may have. Thanks for your donations, too.
Dave