Send a message to the person who requested a photo of the grave monument of Henry Threlfall with the following comment:
I believe this grave to belong to relatives of mine, Agnes and Henry being in my direct descendant line.My research has lead me to uncover some very old photos of (what I presume to be) family gravestones. I'd be happy to share the scans with you if it is something you'd be interested in - in return for whatever information about their location you may be able to offer (a steady Photoshop hand may be required). Please, feel free to post on site too. RTegards,