Hi Jonny - I have followed your sad story and the loss of the original dial. Further bad news is that finding a genuine replacement will take either a huge gesture of goodwill from someone lucky enough to have a spare or remarkable luck either finding your lost dial or another one out there wherever there might be. There was a time when the odd dial would pop up for sale but as prices have skyrocketed so too has this opportunity dried up. Your best option is to find a suitable 1163 dial (Viceroy) which are available and a someone who can refinish the dial to match the original. By going down this road the hour markers and date frame will be correct. Let us know how you get on.
regards
Paul
www.heuerworld.com