Thanks for that, I watched a video on youtube and it said that the filler and drain plugs are single use, but considering that they are metal and have an o ring I would have thought that just new O rings would be fine there as well?
I have a kit at home with a selection of metric sizes so I am sure to have a couple the correct size, but we use reuse O rings all the time at work and providing there is no visible damage they are always ok when reused even under high vacuum or positive pressure.