Thanks, guys. Hi Eric, the ribs are doing a good job of keeping the curvature of the hull, but the hull still flexes a lot from the middle where the turret was, making the ship sag when you lift it up and flatten when you set it down. After I removed the turret the hull just seemed to have lost its spine, much like a jellyfish. And I doubt if my styrene turret replacement will do much to bring back the original structural strength. I may need something similar to John Martin's AMT Falcon in his article where he attached a cylinder down the middle. I'll use it to support the ribs. I'm on the lookout for a 5.75in dia cylinder.