By the years (1960s) that I saw the train coming through Pomona, California, the observation was gone, although the lighted drumhead remained on the rear. In summer and during the Christmas season, the train regularly carried 8 sleepers, the pleasure dome lounge, and diner. The rest of the year 4 sleepers, with diner and dome lounge in the middle, ran attached to the hi-level El Capitan.

Photo above from Classic American Streamliners.