I recently got these parts for my series 111 2.25 diesel. Oil was coming from the screw that holds the breather cap in place on top of the engine. The problem was getting the right part numbers so I could order in but I finally got them. I am posting this here just incase someone else has the problem but cannot get the right parts.
515291 screw set Set Screw - Paddock Spares
232037 sealing ring Ring - Paddock Spares