Short answers, pulled from the story.
Dictys Cretensis, or Dictys of Crete, was the purported author of a diary of the Trojan War, said to have been a companion of the Cretan hero Idomeneus. His significance lies in the fact that his Chronicle, along with the De excidio Trojae by Dares Phrygius, became the primary source through which the Homeric legends reached the Romance literature of the medieval West after knowledge of Greek faded in Western Europe.
A writer named Q. Septimius published the Dictys Cretensis Ephemeris belli Trojani in the 4th century AD. The six-book work presented itself as a Latin translation of an earlier Greek version of Dictys's supposed eyewitness diary.
The prologue claims Dictys wrote his diary in Phoenician characters on tablets of limewood or tree bark, which were sealed in a leaden box and buried with him. In the thirteenth year of Nero's reign, an earthquake cracked open the tomb, shepherds found the box, and it eventually reached the emperor Nero, who had it translated into Greek and deposited in a public library.
Grenfell and Hunt found a Greek fragment of Dictys among the Tebtunis papyri, settling a long scholarly dispute by proving that a genuine Greek original existed. The fragment showed the Latin text by Q. Septimius was a close and faithful translation of that Greek source.
A manuscript of Dictys dating to the latter part of the 9th century was found in the library of conte Aurelio Guglielmo Balleani at Jesi. It was described and collated by C. Annibaldi in 1907.
Yes. Petrarch owned a copy of Ephemeris belli Troiani and used it as his key to Homer. That manuscript is now identified as the Codex Parisinus Lat. 5690, held at the Bibliotheque nationale in Paris.