I don't know anything about cars. I try to date photos based on the buildings. I do know that George's Gateway Club closed in the fall of 1954, and was bought by Bill Harrah in January of 1955, to re-open the following summer as the original Harrah's Club. So no photos of George's Gateway Club are from 1955.

Additionally, the original daytime photo appears to be from the same period as the September 1953 video linked below; across the street in this video is Sahati's Stateline Country Club, which closed in 1953, so that first daytime photo could not be later than 1953:
http://Facebook.com/HarveysWagonWheel/videos/vb.566301810132970/806418766121272

The nighttime photo I posted was obviously from a year or two later (1954-1955), after several additional lights and signs had been added to Harvey's Wagon Wheel, but before 1956, when either a sign ordinance or an epiphany of aesthetic modesty caused Harvey to remove all the extraneous banners and gaudy neon from the front of his Saloon, as seen here: