Thomas, The Injection pump on your TD6 is quite different than on my MD. I have never seen this type of a pump. I still think that you put oil in through the cap up to the level of the test port that you call a "T". Now if your diesel pump is leaking bad, they will fill with diesel and diesel oil will run out the test port.
2nd, something seems very wrong with how your diesel lines are connected. The filter you see with the glass jar is a water trap. The line that is disconnected from it should be the input line that goes to your tank. It is open. Is this where you see diesel coming out? Apparently someone by-passed the water trap. I also assume you removed the starter.
Normally the output of the water trap would go to the 1st stage filter, than to tranfer pump on the injection pump, then to final filter, and then from the final filter back to the injection pump. But it looks like from what I can tell on yours, the line goes from the tank to the transfer pump, then to your single filter, than back to your injection pump. The open line you see coming off the water trap might be the return line back to tank. All these MD & TD6 diesels have a return line back to the tank.
Since I am not familiar with the pump on your TD6 and how it seems to be plumped up, not sure I can advise you what more to do. Maybe someone who knows this pump can give you some advice.
The other thing you could do is post these pictures on the Farmall site. There are probably more folks on that site that are more familar with IH gas start diesels and with your pump. Maybe they could explain why your plumbing is not as I would expect. Hopefully someone will know that pump and be able to help you.