Although everything came out ok in the end I made the classic mistake of being overconfident going into this. As it is a study I was concentrating hard on getting the colors and values as close as I could (apart from some of the grey shadows which were too drab) and I almost lost my way. Lesson learned – never let down your guard or watercolor will bite you.
Here is the original photo.
And finally I made a video of the painting process for those interested.