George mate i know of a old trick which i have used in the past and it works without any problems ... i've had a couple of Tamiya kits with this problem .. first i fit everything inside the hull which needs to go there ..then glue the upper hull to the lower and then wrap it with good sticky tape ..then you aline the upper and lower hulls to the seams match , a good idea is to wrap the tape long ways aswell that way the entire thing is stable and solid and will dry square .. the glue of course glues it and the tape helps it to hold its shape .works really well ..worth a try if you other chats suggestions dont work
Some times this problem can be a real pain in the you know what ..good luck mate .
Phill