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/AVvXsEjjBNahBvgNO0ba9HPlwoa6qszeW_6XXY0_7JzbJqdEonDf_Yr70jcmfOTHTvir1ctj777sNDvyoVN7060eqXLd1y-DsPBrqyiJTMD2E1MhyeVnngA6P6hCmvUsX8IXmzVojQBTm0-N8xY/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