In the recent issue of Archiv für Papyrusforschung 60/1 (2014), Brent Nongbri has published an article on "The Acquisition of the University of Michigan's Portion of the Chester Beatty Biblical Papyri and a New Suggested Provenance."
The title perhaps sounds too optimistic in regard to provenance—to cite the conclusion:
The goal of this paper was two-fold – to clarify the history of acquisitions of Beatty biblical papyri and to reassess what we know of the provenance of the find. I am reasonably satisfied with the results of the first task. As to the reassessment of provenance, I think dissatisfaction is the order of the day.Brent has kindly made his article available here.