This is sort of my point. When a car has been changed from factory, it's impossible for us, "here" to guess "what's there" by remote control. You of course don't HAVE to wire the car per factory, there are other ways.
However, the starter relay is one issue that because of the neutral switch or clutch switch is pretty much "there." Even if you have neither of those, wiring it is pretty straightforwared, right off the original diagrams.
THE ONLY ADDITIONS that should be connected to the relay is power tap---offs to other accessories from the "big stud" which is essentially a battery terminal