Geo. Spencer Co., Inc, (DMG Precision Machining), located in Santa Ana, California, has been solely owned since 1987 by Dennis Greene. GSC, founded in 1972 by George Spencer, proudly provides innovative precision machining for the medical industry, JPL and NASA, and other business sectors. Using the Virtual Gibbs system, the firm specializes in all computer formats and CAD/CAM services, including R&D. With large-scale machines from Fadal, Okuma, Bridgeport and Harding, DMG Precision has provided quality machining for the Mars Pathfinder missions, the Space Shuttle program, experimental heart valves, dental cameras, endoscopes and functional futuristic pieces and parts. Many of the NASA/JPL projects and their parts reside proudly as part of several NASA displays at the Smithsonian National Air & Space Museum in Washington, DC. The company is a member of the National Chamber of Commerce, and participates in local charitable efforts.

Dennis Greene, a graduate of Buena Park High School and long-time Orange County resident, is also known for his high Desert off road racing career. He began in 1970 in the Southern California Motocross series, racing at venerable parks such as Saddleback, Carlsbad and others. His love of speed and natural balance led to victories and trophies, and to the off-road races of the Desert Racing Association and District 37 in the Southern California deserts and then Baja SCORE races include the Baja 500 and Baja 1000 in 2006 and 2007.