In this paper I present a pilot case study of three different university mathematics instructors who implemented the same primary source project (PSP) as part of the Transforming Instruction in Undergraduate Mathematics via Primary Historical Sources (TRIUMPHS) project. I describe four implementations (two by the author, two by non-author instructors) using a combination of student and instructor interviews, instructor implementation reports, and instructor and student surveys. Survey data revealed that most students reported perceived academic gains from their work with the PSP, with the author’s students reporting some of the greatest gains. I conclude that there are differences in implementation based upon observed lines of communication and how instructors view distinctive features of the implementation, including the importance of group work and understanding language use within sources.The author stressed the importance of group work and the productive struggle associated with language, resulting in a different implementation than both non-authors.