Sorry, I do not know where they married. Their obits have them married in 1920. It seems like they should be in the WPA Bluebooks for Elkhart Co.,IN. which ended in 1920. I do not see them listed.
Samuel Ganger was my 4th gr-grandfather, he was a brother to your ancestor John (born 1809). I can help you with Iris's parents and grandparents. If you would like, you can e-mail me at: firstname.lastname@example.org