The shoulder is the hardest part of the Dalek to make. The 2nd hardest item are the shoulder slats. Getting them to mate tightly and uniformly to the shoulder curves can be a major headache. It was for me. I finally gave into the EverCoat Rage to fill in the gaps. This stuff is wonderful (but expensive). I used painters blue tape so it would not adhere to the fiberglass and then sanded the sides flush. It solved my problem. The following pictures shows the gaps after the wood was routed for external appearance but you could see the gap without the wood filler.