Of tangential relevance to this blog (relevant for comparative purposes) is the article by Paul Foster, Edinburgh, in the latest edition of New Testament Studies.
'Are there any Early Fragments of the So-Called Gospel of Peter?', New Testament Studies 52 (2006) 1-28. Here's the abstract:
The first text in the Akhmîm codex discovered in Upper Egypt in 1886–87 was confidently identified as the Gospel of Peter, mentioned by Eusebius in his description of the activities of the second-century bishop Serapion. Although the Akhmîm text is dated palaeographically between the seventh and ninth centuries, it is seen as being a witness to a text that dates from at least as early as the second century. This position appeared to have been strengthened by the identification of a number of early papyrus fragments as belonging to the Gospel of Peter. This paper calls into question such identifications, and consequently suggests caution should be exercised before too quickly making the conclusion that the text from Akhmîm is to be identified with the second-century Gospel of Peter.