Here’s a March, 1955 brochure describing Union Pacific’s new American Car & Foundry-built dome cars. The domes in the coaches, say the brochure, are distinctive by having “divan-type seats” that are angled so “the aisle seats are slightly forward of the window seats.”
The brochure fails to mention an even more-important distinction, which is that the domes are more than four feet longer than Budd domes but have the same number of seats, thus giving passengers several inches more legroom. The typical Budd dome had 37-1/2 inches between seat centers, while the UP domes had 46 inches between centers, meaning more than 8 inches of additional legroom.
The brochure is illustrated exclusively with drawings, which is typical of rail advertising that is prepared before the cars are actually available to enter service (and photograph). I don’t see any signatures on the drawings, but their style is consistent with work by the Willmarth studio.