This is a small but important difference, and should be solvable by creating daily harmonic charts for the date of death, using each birth time and seeing which more accurately reflects the death and its cause. While my copy is a third printing, published in 1993, the data was first published in 1953. He opens the chapter with several pages devoted to the importance of accurate birth data. However, Marc Edmund Jones, often referred to as the Dean of Modern Astrology, in his book The Sabian Symbols in Astrology, in Chapter 13, page 355, gives Lewis birth time as 8:35 AM. Wikipedia gives the date of July 14, and also July 15, however no particular time is cited. Lewi predicted his own death of a cerebral hemorrhage at the age of 49, to the minute, according to Astrowiki, which places the time of death at 12 noon on July 15, 1951.
One of the most important contributions for which were in his debt is the Saturn cycle of career success. He wrote for, then became the editor of, Dell Horoscope magazine and also The Astrologer.