Baxi 80e hot water diverter

[Ringer60]

First up, the reason for the question is because I have made a schoolboy error, so please don't beat me up too much!
I am about to replace the diaphram in the diverter valve and have the kit all ready.
In my excitement to get the job done I didn't make a proper note of the sequence of parts when dismantling. Idiot!
So, can anyone tell me please exactly where in the sequence the little O-ring goes?
Help!

 

[gas112]

Once front is on it goes on the pin before the gland nutand silver washer go on

 

[Ringer60]

Top man, thanks.