That is a Plymouth DL, repowered... originally it would have had a Buda or Climax engine. It was their most common model, so may be hard to trace. The builder's plate would have been on the forward roof support, so is very likely long gone. Of course Old Vegas was the home of Dan Markoff's Eureka.

Have your friend contact me off line. I have a lot of Plymouth DL literature, and own a 1922 DL-2. I live about 2 miles from the site of Old Las Vegas.

Randy Hees

Director, Nevada State Railroad Museum, Boulder City, retired
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