You said the generator ran like a motor so it isn't cooked. My 39 P/U has a voltage regulator on the fire wall?? Check and see if you have battery voltage at the wire from the battery to the cutout, this is the wire going to the cut out. The other wire on the cut out go's in the generator. If you have voltage at the battery terminal you could hook up a voltmeter to the battery, start the engine and set the RPMs at about 15 MPH and touch a jumper wire across the 2 wires on the cutout watching the voltmeter on the battery when you touch the jumper if the voltage comes up up on the voltmeter the cutout isn't working. You can grind the 3 spot welds on the bottom edge of the cutout and remove the cover. Clean the points and hook up a DC variable power supply from the body of the cutout to the generator terminal. You also need a DC volt meter that shows what the voltage is as you bring it up. The points should close at 7.3 volts. If it is higher loosen the spring tention so it pulls in at 7.3. If lower increase the spring tention. Check across the contacts when the relay is pulled in to see they are making contact. A 6 volt bulb from the battery terminal to the body will light when the contacts make, this also makes it easier to get the points set at 7.3 volts you can see exactly when they make as the bulb lights. When finished solder the cover back on at the 3 spots useing acid flux. G.M.
