only two are unlabeled. One would have to be the videographer's and the other would be the one Marilyn Briley's wore after she gave up the phallic-electronic one (see post #385.
Among the video frames, neither Bruce Briley nor the pilot are seen to wear a life jacket. Those two and Ms Fuddy seemed to exhibit a fortuitous ability to float without one. (Ms Fuddy's legs and feet are atop the water even though her life jacket is four feet toward her head.)
Since the second infant life jacket was found with an unpunctured CO2 cartridge and Ms Fuddy was seen at the starboard fuselage with a fully inflated (adult) life jacket, as also seen at the end of the scenario on the replacement diver:
Since the replacement-Fuddy also exited the scenario, it might be considered reasonable that the NTSB didn't collect the one he was wearing, which may well have been the one Fuddy also had worn prior to exiting the scenario. After exiting the scenario, she would have no further need of it.
No one is seen to be wearing the infant life jacket that had an unpunctured CO2 cartridge that the NTSB found.
(Or shall I say, "claimed to find?" Surely the NTSB's spotless reputation should not allow our minds to consider whether the NTSB would make any false representations or do anything inappropriate with evidence, right?)