Send a message to the person who requested a photo of the grave monument of John Pratt with the following comment:
John Pratt was the brother of my Great Great Grandfather, David Pratt. I have been researching my family tree for many years and would very much like an image of the grave to add to my research. It would be much appreciated. I will definitely acknowledge receipt and if I can be of any help to the project I would be pleased to help.