I have also build a Pyro by now, adding the cockpit I have created. It took me a while to figure out how to get the fuselage together. Could it be that it just doesn't fit accurately?
Unlike andersonmr34 I haven't left the bottom plate off but rather left away the engines. To attach the wings it was a huge help to have access to the inside of the fuselage.
Here are first some pictures of the cockpit and the fuselage.