The Presbyterian Historical Society has processed the Peacemaking Program Records as Record Group 542, and the guide to the records is now available for researchers: https://www.history.pcusa.org/collections/research-tools/guides-archival-collections/rg-542.
The collection totals 59 boxes, with a scope covering the history and actions of the Presbyterian Peacemaking Program (PPP) and its staff as they worked to find ways for the denomination to respond to Christ’s call to be peacemakers. Additionally, there are records of the Presbyterian United Nations Office (PUNO) and the files of the Rev. Donald J. Wilson, chiefly documenting his work in peacemaking and international affairs before the creation of the PPP.