The founder of Tucker Sno-Cat Corporation was Oregon-born E.M. Tucker, Sr. After his 1964 death, Sno-Cat was taker over by his son, Emmitt Marcus Tucker, Jr.
I believe that the L.M. Tucker at Royal Aircraft Establishment was Leslie Tucker. If so, he initially worked for de Havilland, Handley Page, and Vickers. After WW2, Leslie Tucker went to the ill-fated Planet Aircraft before joining the RAE at Farnborough (~1950-75).