Born in Langham, England on August 11, 1915, Leaver immigrated with his family to Saskatchewan, where he received his schooling. In the 1930s he invented and developed an automatic landing system for aircraft. During World War II, he worked in the radar industry. After the end of the war, he formed Electronic Associates Ltd. with colleagues from the radar factory and in government. The company developed a robotic machine tools system, patented as AMCRO (Automatic Machine Control by Recorded Operation) in 1947. They specialized in developing electronic instruments such as field Geiger counters and other survey and automatic industrial process controls. The firm was eventually taken over and became Sentrol Systems.