Well, I did find something that is warped, but it looks like it is due to the the screws that hold it onto the opening in the lower hull. This ring is the base for the turret to rotate on and it is clearly warped, but I am not convinced that it is the real problem. I am going to place a small section of styrene under this ring, at the back, to make the rear of the turret raise up 'slightly'. I hope it works! []

Chad