Clara Ising is my great-great-great grandmother. My great-grandmother was named after her. You, actually, have more information than I have on the family. I have Joseph's wife's name as Catherine and their one son as Gustave. Clara married John Gottlieb and they resided in Iowa.
I've attached a copy of Joseph Ising's obituary that I found.
I may have more as I don't have the dates in front of me.
I hope this helps...