Lets start out with a few old station images.

Heres a picture from 1931 of a Diamond station in the process of being built. The station building itself is complete. Notice the visible pump lying on the ground in a crate, and the first-generation station ID sign on the pole.

Here we have an advertisement from a building/signage company with an extremely cool Diamond facade.

Here is a Diamond service station building in Louisville, KY. It was built in 1927 in the mission style, and has some very cool diamond-shaped tiles on the pillars. Notice the metal brackets above the two main arches. These are likely from a Diamond Service Station porcelain strip sign.

Heres an image of some clockface pumps at a D-X station in the mid 30s.

And a much newer DX station From gassigns.org: Abandoned DX on US 77, south of Wynnewood, OK about to be demolished.
Photo taken by John Cirillo, 1997.