A huge thank you to japeflakes, Pat, John-76 and Skippy for the great clean up of "Thomas's" photo, and the back of the card as well. It is one of the oldest photos in my collection and thanks to both Gaget and Jim, I can place a date on it, and can positively call him Thomas Duggan, born 1852 - died 1926.
In the past when I have tried to identify the person in a photo, I have compared facial features, but this time, I discovered something more unusual. I always thought the unknown person in the photo must've broken his hand at some stage. Then in another photo, taken of Thomas Duggan aged 73, in 1925, I thought, oh, he has bad arthritis in his hand. Then yesterday, I thought, that hand looks familiar. What do you think?