Hi Hande, it's hard to tell from the photograph but, to me at least, the bulwark quarters look too far bent round. I can understand the theory regarding getting them hard up against the supports but my view is that if you affix the stern part first, when it comes to forcing the side part in place, there is a very real danger of the dreaded "snap". Fitting them on the side first will merely have the same result.
The Solution ?
I would soak the effected parts in hot (not boiling) water, allow to drain off, them fit them while still damp and peg into place against the supports and leave to dry completely.
Once dry, they can be removed, they should then retain their shape and can then be glued in place and clamped until the glue has completely hardened off. (24 hrs)
Hope this is of some help to you.
Regards,
Ray.