My July1969 and Jan1972 USCARs have N3739G registered to: SS&T Aerial Contractors,
Phoenix, AZ. And tanker C30 is reported (note1) with T&G Aviation of Chandler, AZ
from 1975 to 1991 when it was sold to the Lone Star Flight Museum, Galveston, TX.
So it was probably being operated by SS&T at the time of the photo.
N3739G is currently registered to the Texas Aviation Hall of Fame in Galveston with a registration date of 24Jan1991 (23Feb2003).
Another RonsArchive photo of this a/c.
Note1: This info is from the excellent March/April 2003 Warbirds International "Privateer" article by Milo Peltzer and Bob West (pg59).
Google: PB4Y-2 Bu59819