Simon not bad. The rocker arm, indicated in black, goes to the other side of the fulcrum, just like the exhaust/inletvalve rocker arms. The valve rockerarms engages the valvespindle in a slot. I am in doubt about the valve you have placed on the control airpipe to the top of the valve, do you have a picture of that? Below on my picture I have tried to explain a bit more on the details.
Tore