Not only a Mercer, but at least one Stutz K series Bearcat, and a Jordan Playboy.
Several Hudsons, and everyone recognized the Buicks and Model Ts, but did you also catch the Model A Ford (the first model As, not Henry's Lady), a model K Ford, and the International Harvester Motorwagons?
Not to mention the Fiat Mephistophole, and the racing Benz. Strangely absent, although they would have been relatively contemporary then, were any Duesenberg, or Cadillac.