The distribution list of 1974 remains online.
The Glasgow Oxyrhynchus papyri have images online.
There is a catalogue of the papyri at St John's College, Cambridge.
The Westminster papyri were edited by D. J. Crawford and P. E. Easterling in The Journal of Egyptian Archaeology 55 (Aug., 1969): 184-190.
The British Library's papyri (highlights thereof, such as the Athenian Constitution) are being digitised.