I did some digging on C.B. Lewis, the guy reportly she ran away with. The Clifford B. Lewis that is referred to in the news articles later committed suicide at his trailer park in 1975. He was born in 1919 in Joaquin, TX, and at some point prior to 1940, joined the navy (he's listed as being in the navy in the 1940 census). It appears from the draft card that he was discharged at some point after 1940.
A B Clifford Lewis born in 1920 in Texas is present in the 1950 census, and is listed as an inmate in a jail in Ogden, Weber, Utah. It is possible it is him, and a criminal record may explain a change in career from Heavy Equipment Operator to truck driver. I was unable to find criminal records in Utah, so the question is still up in the air. His Huntsville Prison record lists his marital status as divorced as of 1954.
His obituary lists three children all without his last name (possibly was an absent father?), and a widow. His findagrave profile lists him being married to a Bobbie Coward in 1970, who married another man two years later, just three years before his suicide. It seems he married another woman shortly after his marrage to Coward, up until his death. I feel Lewis may have been a serial marryer, as his marital status is in constant flux throughout records. That could be a subject of future research.
That all is to establish Beverly Mastny was not a signficiant figure later in Lewis' life.
Beverly Mastny's father and grandfather were both truck drivers and my personal speculation is that Lewis lured her into following him through a shared truck stop or work place or something.
Anyway, I had some freetime today and decided to take a look at this case. This is just what I've been able to find, and I added some records which I felt are the most crucial in establishing his identity. Being the only substantial lead in this case I thought I may be beneficial to do some digging on this person. I had to cut down some files for space, so let me know if you would like images of better quality or want my specific sources.