Identifying Old Photos of Possible Ancestors

Sometimes genealogists find photos in the family collection which cannot be identified.
I wish I could tell you the occasion. Wedding? Reunion? Holiday? Funeral?

This photograph was taken at a McCollum Family Gathering of unknown date and place. I can only identify three of the people shown: seated on the far left is Charlie McCollum, standing fourth from the right is his second wife, Martha Merriwether McCollum and seated in front on the far right is a son of one them - I just don't know which son. So if anyone can help me identify whose home provided the setting for this family occasion, I would really appreciate it. The McCollum family first lived in Putnam, Callahan County, Texas and most of them eventually moved to Lockney, Floyd County, Texas. If I knew when it was taken, it would pretty much clear up the locality. Wouldn't it be great if the home was still standing?

The identity of the people in the photo below has been debated among our family. My dad believes it is Mack and Mary Cannon Duke while I believe it is Tom Adams (Mary's step-father) and his first wife, name unknown.

Update: Tom D. Adams' first wife was Isophena/Isavena Bulls.  They married 18 December 1883 in Bell County, Texas.  McCoy (Mack) Duke and Mary Cannon married 2 December 1900 in McLennan County, Texas.  Someone, we don't know who, wrote on the back "T. D. Adams, Bruceville, Texas". Bruceville is in McLennan County.  So it comes down to style.  Are they dressed for 1883 or 1900?

Searching for your ancestry can sometimes be frustrating and it helps to publish photos on the Internet in order to find other family members who can clear the muddy waters.