So I was wrong. The diagram was right(sort of). There is a spacer as per the attached photo which is different in shape to the part partially shown in the diagram. This difference was what got me scratching my head. Six round spacers is indeed the correct number.
I've attached a photo (I hope it works) of my second parts unit which shows the condition my main unit was in, plus a photo showing some of where I've come to. Great having my little daughter to help! I know the colour is wrong and though I do semi regret it it would have cost an extra $100 to get the right colour in rattle cans, so I can live with it as is.
