[save_old_iron]

I'm of the opinion this is not a part that has been "failing for 40 years" but an improper component fixed to the ignition system some 40 years ago. The value of the capacitor most likely restricted the "ringing" of the ignition coil and resulted in a very short and therefore weak spark event.

The condenser does keep the points from arcing, but that is not all it does. The interaction of a proper condenser and a proper coil allows the time a spark is present between the plug electrodes to be lengthened. The spark is not just one quick spark but one extended spark event lasting a few thousandths of a second. Think of the spark as the sound of a hammer hitting a bell. The bell "rings" for a certain length of time. If you put your hand on the bell and hit it, you get a sound - a short thud. This short thud is what kept your tractor from starting properly under colder, more challenging conditions.

Good find. Keep the points clean, the carb clean and do a static timing. You will be surprised how quickly the old Kolhers will fire up.