"Frederick Leupold (1875-1944) and Adam Volpel (1875-1940) founded the company Leupold and Volpel in 1907.  After the death of Mr. Volpel in 1940, Mr. J. C. Stevens bought out Mr. Volpel's interest and thus the name became Leupold & Stevens Instruments, Inc. in Portland, Oregon."

Reference:  Smart, Charles E.   The Makers Of Surveying Instruments In America Since 1700  Troy, New York:  Regal Art Press.  1962