Time to update this thread with my latest find fresh from the National.
Here is what I believe to be a partial 1907 RPPC showing the first incarnation of the 15 card initial set with the Cobb Fielding pose.
Attachment 324883
The back looks like this. The other RPPC back is the one off of the well-known 1907 team pose RPPC shown below for comparison.
Attachment 324885
Attachment 324882
Here is the back of another copy of the Detroit team RPPC, listed online, showing the AZO four diamond box.
Attachment 324884
My guess is a collector bought the advertised Dietsche set when it first came out, including the Fielding Cobb, before the Batting Cobb was available. He wrote the names and positions of the players, arranged them in a group of 15 with the manager Hughie Jennings in the center and overlaid the Detroit Tigers 1907 over the Jennings postcard. He then photographed them, created the RPPC and sent it to a woman (note the "Miss" in the address portion on back). Somewhere along the way the likely blank white front excess was trimmed away.
The back of the subject postcard has the same back as the 1907 team RPPC as shown above. The AZO four diamonds stampbox was only printed from 1907-1909. The AZO four triangles from 1904-1918. My guess is 1907 as it is very unlikely he would have bothered to do this at a later date.
At the very least this is one of the earliest examples of a baseball collector at work. I have never seen another example of a photo of an early card collection. At best, I'll kiddingly suggest it is a 1 of 1 version of the 1907 Ty Cobb Fielding RPPC. Whatever it is, I'm excited to find it!
Now here is where I'd love some help. Can anyone find me one of the 15 cards depicted in the RPPC with an exact match for the handwritten name and position? Do these copies still exist, I'd love to own one or at least see it and check if it has a postmark on the back.