Due to a typo on my part, I originally visited an incorrect location. Many thanks to David Metcalfe for pointing this out to me. The post and accompanying photographs have now been corrected.
The first location, at 3340 S. Michigan Ave., was listed in 1915 as being the home of de Laurence's Order of the Black Rose. That same year the Order's address was also listed as being on Wabash. Whether the Order moved, or whether the local press confused de Laurence's organization with his publishing headquarters is unclear. Unfortunately the original building no longer stands, and this location is now occupied by a generic building on the Illinois Institute of Technology campus.
Also in 1915, this location on E. 47th St. is listed as his home address.