"The Mottice family moved to Waynesburg in 1920, and lived in what is now known as Frank Miller property on S. Main Street. The home at the time was owned by my Grandmother and Grandfather Dieringer."
I don't ever recall seeing that house, and my impression is that it was torn down sometime after the 1940s. (Grant died in 1938, Bob wrote this in his memoirs somewhere between 1947-50, and by 1948 Frances is living — perhaps with Ruth — at Queen Court in Canton.) Moreover, I don't know what prompted the family to move to Waynesburg — although it may be simply to be closer to Frances Dieringer Mottice's family, several of whom lived there. I had heard about the house being purchased by Frances' mother and father, but had no details.
I recently came across a document among my father's papers that sheds a bit of light on the situation. It is an executor's deed regarding the estate of W.D. Rennie of Waynesburg dated Aug. 2, 1920. Upon his death, Rennie bequeathed his house — identified as "lot #32 in the Village of Waynesburg" to his daughter Eva for as long as she wished to remain in Waynesburg. His will stipulated that, should she ever move, the house was to be sold that the proceeds used to purchase another house for her.
In this deed, the executor of Rennie's estate states that the circumstances were met for the house to be sold, and that he was selling the house to "Frances Mottice and her heirs" for the sum of $1,800. There is no mention of Grant Mottice, but also no mention of Frances' parents (her father died in 1918). But it seems very likely that this is the property Bob Mottice describes as the family home when he was a child.