In Cadillac often there are no model names at all, just trims (in older ones). That's also maybe why for these we used trim name as model name. Maybe in that case keeping Brougham in model name is better?
For Cadillac, usually we rely on MrCadillac up to 70s, and on Benzilla & drujon for 80s and newer.
MrCadillac has a site with lots of pics: http://www.car-nection.com/yann/dbas_txt/indx2001.htm