Construction A section of the secondary hull needs to be cut off to facilitate the new hull section that will hold the horizontal pylons. Again you'll notice the paneling sections are the same as the injection kits. With a little milliput to close the gaps and seams, you can't tell the difference. Building the Constitution - class parts were pretty standard. You'll replace the bridge, dorsal section and pylons with the vacuform parts.
Extra care is needed on the third vacuform nacelle.
First of all, the thruster section on the winglets at the rear end of the nacelle are too small and it doesn't match the original kits. This is easily remedied. Cut a strip of styrene plastic and attach to the front of the winglet, then use another piece of styrene to join to the back of the nacelle. Use a little milliput to fill up the empty space in the triangle and flatten the top and bottom, then sand to flatten the surface to fit the other two nacelles. Another problem with the third warp nacelle appears at the front at the warp drive intercooler.