Ehrhardt (1964: 18, 11), who dates the [Muratorian] fragment probably to the episcopacy of Zephyrinus, 197-217CE, and who considers Irenaeus to have been one of the authorities behind the fragment, suggests that the fragment's treatment of the Apocalypse of Peter as a canonical book offers a terminus ad quem of 240 CE. [The Reception of Luke and Acts, Andrew Gregory p. 41]
And then the original reference in Ehrhardt's the Framework of the New Testament Stories:
If my analysis is correct, the Muratorian Fragment will appear as a product of the Catholic Church at Rome, probably under Pope Zephyrinus (ad 197- 217), the successor of Victor I. Regarding the first it will appear as a milestone on the way to the formation of the canon of the New Testament marking the occasion when the four Gospel canon was established in the Church at Rome. [p. 11, 12]
dating back to conversations with his grandfather, Gaston Frank. "He said we represent one of the last descendants of the Frankist Jewish faith in the world," he muses. "I grew up thinking that our family was something like the Last of the Mohicans."