First if all WELCOME!!!! We are a slightly crazy but nice group of folks and very supportive.
On the tail turret, from my experiences with it, one big thing is to take your time, and DRY FIT the parts like crazy. The side pieces have to fit just so over the base. The side walls of the outer rounded pieces shouldn't be glued to the "glass". THey have to go outside the lower ring and top curved part.
Here's a link of my build to show you what I mean.
http://i88.photobucket.com/albums/k173/ ... G_2956.jpg
The fuselage is bad, but the turret is good. Hope this helps.