Hi. My grandfather, Laurence Kammert, was born around 1883 on a farm in Tinley Park, Illinois, which is just outside Chicago. He was the youngest of 13, but I only know the names of eight of his siblings. Your grandfather could be one of the "missing" siblings. The other siblings that I know of are John, Wiliam, Christian, George, Mary, Margaret, Lilly, and Elizabeth.
I believe that my grandfather never met some of his siblings because they were married and gone before he was old enough to remember them. Your grandfather was 19 years older than my grandfather, so the timing is right.
If you think that your grandfather and my grandfather were brothers, please let me know. If they were brothers, your great grandparent's names are Margaret and Henry. I hope this helps you in your search.