I know you are not trying to be argumentative, and I certainly appreciate that! But I am not sure what online resource you have been using for that coil. That Delco number was used for quite a few applications, including 1950s through 1960s chevrolets and, interestingly enough, Studebakers, among others. Chevrolet even used that coil for the bigger W motors and was over the counter for quite a few years. All of those applications used a ballest resistor. You have to use a resistor with a coil that designed to be used with a resistor. The wiring for these coils generally provides a full 12 volts when the key is on start (bypass the resistor) and then when you release the key or starter button from start, the bypass ends and the voltage flows through the resistor which knocks down the voltage to the coil to like 8 volts or so which not only protects the points from over heating, pitting and burning (which were designed originally for 6 volt applications), but also to keep the coil from over heating.
Now it is true that some later coils were designed to be used without an external resistor. The Delco coil you listed does not appear to be one of them. Besides killing the points, over heating the coil is not good for the coil.
The points do not function at their best if the point contact surface is pitted, rough or badly worn. And frankly, you cant really tell whether the points are rough or pitted by eyeballing them, unless of course the pitting is really bad. Years ago, mechanics would file the points down with a thin point file to get more service life out of a set of points. Turns out, while this workd for a bit, it was not optimal. Points are not that expensive, neither is a firewall ballest resistor.
If I understand correcty, this truck was converted from a 6 volt to 12 volts at some point. Six volt systems did not need or use a ballest resistor. That came about with the change to 12 volts and a resistor was the easisest way to deal with the increased voltage early on. You might consider taking a close look at your wiring (ignition switch, starter solonoid/button), and ignition (coil and distributor). You should then sort out a way to add in the resistor (12 volts when turning over and starting via a bypass, knocked down voltage once the motor is running.)
I am not saying this is your problem, but it could very well be part of the problem.
