The project in Clarence Victor Derr's carriage house

This is my great-grandfather Derr, late in the 19th Century.  I have no idea what the model is for, or who built it (though I can make a pretty good guess) or if it's supposed to be a representation of an existing structure, or what.  C.V. Derr was not an architect; he sold sewing machines.  Has no garage in my family ever been used to house vehicles!?