Confounding. What can the "Phila" on the shirtfronts suggest other than Philadelphia? And the "R" would certainly suggest
Reading, which has had a farm team, long associated with the Phillies, almost continuously since the 1880s. And yet,
neither the A's nor the Phillies ever wore a uniform matching the "Phila" unis seen in the photo, at least according to
http://exhibits.baseballhalloffame.o...ines/index.htm
Perhaps a better view of what's in the background might help...