The company (electrical contractor) I worked for in the late 1950s had a 1/2 ton Studebaker truck for a service vehicle. It was serviced by the local garage which was next door. After a service, which included an oil change, one of our employees picked up the truck and used it for a service call about 3 or 4 miles away. When he finished his job and returned to the truck he noticed a small pool of oil underneath. He checked the oil and found nothing on the dipstick. Apparently the local garage had forgotten to install the drain plug and maybe the oil before the truck left. They sent a fellow over w/the drain plug and 4 or 5 quarts of oil. The company had the truck for several years after that w/no problems to the engine from the lack of oil.