Not exactly an interior shot, but a nice view from the flying bridge looking down at the radio man in the hatch to the radio room.
In the lower left is the K-Tube reel and float. The dark-colored small floats on the cable are coated with phosphorescent paint to make them visible at night, as a means of determining the angle compared to the bearing of the boat of the reeled-out line.
In the lower right is the fuel hand pump, used for moving gasoline from the second tank to the main tank.
From a collection of photos of a crewman of SC 254. Thanks to Laura Hawkins for submitting the images to The Subchaser Archives.