Do you have a parts books for the tractor? Look up front PTO. The picture here is for the 6 cylinder TD6-62 series, its to give you an idea how the front PTO is attached, yours may be different, Item 7 (Coupling) is steel on my tractors, it attaches to the drive of the pump. I have never seen it in brass. You can check with some of the wrecking yards (FP Smith in Fairfield, CA would be a good one) You may have to have a machine shop make the couplers for you. Parts books are good sources in that you can see the sequence of assembly. Hydreco pumps are what were offered from IH, they are good pumps, have a hydraulic pump shop check it over, they are worth fixing. The pumps are hard to turn by hand.