I finally managed to speak to and meet with Mary Godwin, museum curator at Lyme Regis museum. Mary had been away and only got my email requesting a resit on her return. When I explained that I wanted to retake the picture of her on the stairs with an ammonite she was quite happy to co-operate, it was just a question of co-ordinating our diaries and today was the day.
What I hadn't realised was that, although I had included part of a portrait in my original picture, there were in fact four portraits on the stairs behind Mary. I went back to the museum whilst Mary was away and took some pictures without her thinking that I could 'Photoshop' her in, but this proved too difficult to get a good result.
In the meantime the date for submission of the full module came round and I had to send it all off minus a retake of Mary otherwise I would miss the deadline.
Here is my final missing picture, hope it was worth it!
Here's the details of the shot:- f11 @ 1/125 with a focal length of 24mm, I used the oncamera flash reduced by one stop so that it didn't create a harsh light and heavy shadows behind.