I would make every possible attempt to join all the broken pieces into one " chunk". That should be sufficient to see what is missing and what needs to be done. And you would have something to use as a reference as Mr. craigd has suggested. Good wood glue and epoxy are your friends to get started here.

Since you have carving experience it should be clear sailing from that point on. Just take your time and set it aside any time you get a bit frustrated.