Rancho Camulos owner August A. Rübel's copy of the American Field Service Association Directory for September 1931, listing the names and addresses of ambulance corps veterans who served during World War I, living and deceased.

Rübel is listed on page 53 (pdf page 55). The "13" in front of his name means he served in Section 13. (Other sources say unit S.S.U. 631.) The "'17" after his name means he served during 1917, although he apparently served until 1919 when he was discharged. (The U.S. Army took command of AFS when the United States joined the war in 1917.) His occupation is listed as "rancher, Camulos Ranch," and his given address is Camulos Ranch Corp., Piru, Calif.

Rübel has marked several names in the directory, presumably people he knew.

August Alexander "Buddy" Rübel was born July 6, 1899, while his parents, New Yorkers August Alexander Rübel and the former Florence Taber Toel, were vacationing in Switzerland. He grew up on the East Coast and volunteered for the American Field Service — the noncombatant ambulance corps — during World War I, serving in France from 1917 to 1919.

The AFS re-started at the beginning of World War II in 1939, and the experienced Rübel was recruited to train younger ambulance drivers. In 1942 he went over himself, driving an ambulance in Tunisia. He was killed April 28, 1943, when his ambulance went off the road, apparently having hit a German land mine.