Send a message to the person who requested a photo of the grave monument of Thomas Folliott Powell with the following comment:
I believe this is the grave of my paternal great grandfather. I am sorry that not all beneficiaries of your endeavours have shown any gratitude. I am extremely thankful for your efforts as I went to the cemetery on a recent trip to Edinburgh and although I did not find the grave, I was able to get a feel for the area my ancestors had lived in. So thank you for the details you put on the web that inspired that! I am not a photographer but perhaps could help in some other way.