Mr Stapleton is a naturalist which is why he’s carrying a tin box and a butterfly net. He is a slim, tall man in the photo just like the story told. He’s wearing a gray suit and a straw hat in both. Watson and Stapleton met on the moor. The man in the photo looks to match all the details as Stapleton in the story.

“A moderate walk along the moor path bring us to the merripit house.” “Perhaps you can spare an hour that I may have the pleasure of introducing you to my sister”