It would depend on the arr. back then, whether photog kept rights or GR got them. Usu the photog owns rights to use of the image. To be public domain they have to be crazy old now (to protect Disney, the laws wer e changed cuz the mouse was gonna go pd after 56 years) or specifically intentionally released to the public.
Agreed, but Roddenberry could have hired the photographer.
Star Trek masks were released by the Don Post Studios in 1975, about a year before the photo was taken. See here and here.Regarding the Kirk and Spock effigies, I think we're looking at artifacts that were left over from creating the Movieland Wax Museum dummies in the early-70s.