I haven't opened the Global engine yet, but I thought she would be happier with some oil. There is no obvious place to fill in the oil so I opened the pressure relief and it looks quite ok from there. I turned the engine side to side to spread oil inside. (used synthetic 5W30/5W40 - will obviously remove it when I opened the engine)
At the bottom of the engine, I guessed the oil drain plug is a Hallen M17x1.5. It was sealed with teflon band ! I need to find a way to secure it.