This is probably an 8N with the side distributor.
Since it has the side distributor, the coil may have already been changed. Look it over and see if there is a number or voltage indicated on it. If it's a 6v, a 1.8 ohm ignition ballast resistor should work. If it has a 12v coil, it's probably ok without a resistor, still check for numbers and try to find out if the coil has an internal resistor.
Also check the polarity of the coil. Assuming it now has an alternator, the system will now be negative ground. The + terminal will be connected to the ignition switch, the - terminal will go to the distributor.
The points are different for a side distributor. They are available on this site, at Tractor Supply, or a real auto supply can order them.
While you're in there, feel for side play in the distributor shaft. If the shaft and bushings are worn, the points won't stay set. Also see if the centrifugal weights are free and will spring back when released.
For now though, you just want to hear it run. If it proves to be a useful tractor, might look into electronic conversion, new cap, rotor and wires later.