Close to giving up on this. I'm missing the delivery valve. The place I bought it has stopped selling them, so I called into a bigger one in Inverness on my way back up north at the weekend, which does still sell them. They thought the service kit would sort it out, so I bought that, but looking at it, it's for a 20ml gun and even without opening it I can see the valve isn't going to fit. I've emailed CoxAgri as the UK distributor to see if there's any way I can get a replacement valve, but it may be game over. It's a PASD998, which I can barely find a reference to online, and they're £27.50 new, so at least I didn't spend a fortune on it - the kit I bought at the weekend was £14.77, and with a 220 mile round trip to return it, I think I'll either have to write that off or buy the drench gun it actually fits!!