one last thing the "insert" (part 8 above) is stuck inside the water pump assembly, I assume the o-ring sits in the gap between the two however the o-ring seems to be a smidge too large for it.
I assume the o-ring is sealing the entire water pump to the bottom gasket so I shouldn't be overly concerned about it lining the insert (part 8) perfectly?
Sorry about the constant questions, I'd rather be overly cautious and do it right the first time, perhaps someone else could use this as a guide too!