I too have done a comprehensive search for you on the web and all my trade lit and manuals i have in my office, but alas i have not found any ref to that fire, Cept for Tony1941's link. It is however very important that the cobbles are put back in the corect order according to the manufacture's instructions as it will affect the flame picture and could be very dangerous if not done so, as it could obstruct the burners and incomplete combustion could occour resulting in the dreaded CO killer poisoning threat.
So I would look closer on the fire and somewhere there will be a badge or sticker showing the make and model of the appliance. Once this is established you need to contact them and ask for a copy of the installation instructions. In my experience they are always happy to send them out at no cost. Good luck.