Upper bunk in a Trooper

Hi,  l' m trying to make an upper bunk for my 3 year old grandson. A carpenter has made a lovely job of cutting 1/2 inch ply into 3 sections that fit the "shelf" under the roof.... But the covers for the awning nuts & bolts mean l can't slide the sections back and when notches were cut to allow them to stack, 3 sheets depth got in the way of the roof opening mechanism at the back! Any suggestions please?