ADDENDUM 2/17/22 11:45 AM: The Christy Mathewson is not a supplement. It is printed on pink paper and is part of the issue.
A March 23, 1907, National Police Gazette with a Christy Mathewson baseball supplement. The issue is complete and is in EX condition. The pages are separated from the centerfold and there is a slight spine roll. The Mathewson supplement is in EX condition with a bright, clean image.