Twin 612 (833 in 1940) bears the green and white that superseded Seattle Transit's simplified postwar cream and grey in 1955.
This scheme had been introduced with the Pullmans and newest Twins in 1943 and 1944, and extended to the rest of the fleet as it was repainted.The destination sign is a mystery.
The people look like real passengers, not excursioners, but service 12 E Cherry never passed this way (though, ironically, it is exactly the route now taken by what has become the 3). 1977 photo.
Mystery solved! Go here for the solution