Have ford 1210. Got new replacement ignition switch. Which wire goes where? Old terminal numbers are AC-30-17-19-50. New terminal numbers are 1-4-3-2-5

What is a Ford 1210?
I would Ohm it out(determine which connections are made in the On, Start, and accessory positions.
Then with a voltmeter, find the constant hot. If you have no ground for killing motor on switch, then you should be able to touch it to each of the wires, One will engage the starter, connect to terminal you determined to go hot in start position. When touched to ignition, gauges may work showing which wire goes to Ignition/On terminal.
I use a tone generator and inductive amp to trace the wires back.
Also be sure vehicle is in Park/Neutral when testing wires/starter.

I see it's a Tractor, couldn't find a diagram, May need to order the manual. May have a Magneto to deal with.