Some very interesting information at that link about that series of sleepers. (7 total). Fascinating is the possible existence of another one near Brimley, MI. Purchased to be used as a restaurant in the 1990s and abandoned sometime in the 2000s. The DSS&A sleeper service appeared according to that link to be from Calumet to Mackinaw City. A Railway Guide for the 1920s would probably confirm if Michigan Central carried a DSS&A sleeper to Detroit. Doesn't show it in my 1934 Michigan Railway Guide.