When it comes to mounting the saucer onto the rollbar/weapons pod, I did basically what Adam did with the original, I kept cutting away the back of the saucer under the impulse engines to fit the shape of the weapons pod, and cut down the sides of the weapons pod to fit the area under the impulse engines. The front of the weapons pod needs to be sanded flat until it is level with the top of the photon torpedo launchers. Should you do this, you will notice that the photon torpedos will launch right into the bottom of the saucer hull. That is how the filming model is set up. Adam told me that he made the second version of the Centaur so that the photon torpedos did not have that issue. So depending on how you want your build to look, plan ahead before doing the modifications to the saucer hull and weapons pod. I wanted my build to look like the filming model, so that is how I built mine.