Mason Tourist King (United States) - AllCarIndex

Obscure one-off prototype, the Mason Tourist King was powered by a Continental 6-cylinder engine. It was apparently built not for the general public, but rather to be sold to the Army as a staff car. An unusual design feature was the right front passenger seat, which was fitted to and swung out with the front door. The Armistice at the end of WW1 put an end to the project.

Beverly Rae Kimes & Henry Austin Clark Jr, "Standard Catalog of American Cars: 1805-1942", Krause Publications, Iola WI, 1996, p.936.

The car was fully restored and sold at auction in 2020 for US$200,000.
https://cars.bonhams.com/auction/25839/lot/76/c1920-mason-tourist-king-convertible-campingtouring-car-chassis-no-1-dmv-state-issued-engine-no-561-7r-54480/