The Nethercutt Museum has a section that is a replication of an early car dealership (like the photos from Shorpy)

For the Shorpy photos of dealerships, check out an interior https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-KHSRb3oDWJQIfKmoVf98BU5z4TojC78UcIdohv3A4fWT9nf0zhzOjYz17X-uC7YTQhxJXtwMIxgqPiDjTYwq7-m_epjlUyeTMeWvw-HJXK6jMmbURsoOSLQuHicP49aFjzD0GOkf4x4/s1600-h/cars8.jpg or two in this post: http://justacarguy.blogspot.com/2008/11/automobiles-of-20s-and-before-from.html or an exterior: http://justacarguy.blogspot.com/2010/03/impressive-car-dealershp-architecture.html