Nothing goes on the nipple. it's just the plug for the gear oil. 1 oz of 30w oil. Some people use synth API-tc in there.
The bottom picture is the RAVE system. The hose marked just goes to the pulse port on the crank case.
The oil hoses in your picture are OLD and crusty. I'm guessing if you give them a squeeze, pull, or twist... they will break off. DO NOT reuse them !!!!! You will soon have a roasted engine because of lack of oil.