I sorted mine over the weekend. Wasn't the simple plug and play solution. My jet was actually blocked, nothing would resolve the block, so I've ordered a replacement but for the time being, drilled a hole using a 3mm bit through it so I can at least use the rear washer system properly!
Thanks for the tips on where to find the pipework, though. It meant I could disconnect it where it usually falls off and test it was working, which it was.