Steve,
funny you should ask...
doing some basic fitting and I ran into this. The way the parts want to go together, the centerlines of the nacelles are "pigeon-toed" (red lines) where I believe they want to be straight up and down (blue lines)
Should I enlarge the pockets on the nacelles so that i can twist them to the correct orientation or sand down the center ridge piece and put a new one in the proper place with a strip of half round?
Lou