My grandmother is Clara Elizabeth Arn, a sister to Katherine Elizabeth Arn, your great-grandmother. I have a 10 page chart on the descendants of Adam Arn Sr that I will share with you. You are included in the chart as a child. However, I don't have any Holden info.
I also have several generations of the Schoenhals going back to Germany, including picture and certificates.
I retired from Brigham Young University Library Jan 2000. I am just getting back into genealogy after three surgeries last year. Please email an address so that I can send you what I have or GED it to you.