I've got the valve working but my Trevor regulator is still leaking! I connected it to a fire extinguisher bottle and put on the gas slowly but it started leaking out of the thread between the end cap you twist to change the pressure and the rest of the reg. I don't think the gas is even supposed to get to that bit if the reg. the pressure also seemed to rise a lot, my pressure gauge only goes upto 11bar and it went way past that despite the end cap being screwed up most the way.
Hope that makes sense a that someone can help and diagnose the problem!