Did you get an anwer to your question about Chicago/Cook County death certificates?You can get death certificates for Chicago 1878-1915 from one series of films and 1916-1947 from another.The later group is straight-forward to use; the earlier group has from 1-4 groups of repeating certificate numbers and it can be a bit tricky to choose the right film.(Email me for more info on that, if you'd like.)
You can also get Cook County certificates (outside Chicago) for 1878-1909 and 1916-1922.And, if you need a Cook County death certificate between 1909 and 1922, you may find them mixed in with the Chicago certificates.
Two other tips: If you find a "Missing" note on one of the pre-1916 films, it is likely that you will be able to find a Coroner's Inquest Record (through IRAD) and a Coroner's Death Certificate on a FHC film if the date falls between 1879-1904.And, i you use the Chicago Death Index, 1871-1933 (the microfilm index with addresses) and find an entry marked "OT" you are likely to be able to find a death certificate on the "Out of Town" death certificate films which cover 1909-1915.
If you're local, the Wilmette FHC has all (or nearly all) of the Chicago death certificate films before about 1908, many of the ones after, and the collection seems to grow weekly as they keep them whenever someone orders.