Eric Ralph's Teslarati article SpaceX’s BFR factory in LA spied with four Falcon 9 fairing halves shows several panoramic photos of the site for the future rocket factory. In it, the author says:
From left to right, my best guess for each fairing is PAZ, Iridium-6 Half 1, Iridium-5, and Iridium-6 Half 2.
Question: What visual cues or other information could be used to associate each of these already-used fairing halves with their launches? Are there hidden markings, or other distinctive features?
Open these large images in a new window to view them full size:
below x2: from Teslarati. Photo credit: Pauline Acalin