Yes - Richard William Whitford was your grandfather.Richard was married twice, once to May (Mamie) E. Cook in Wisconsin and his second marriage was to Charlotte Richeson (thus, your father's middle name), daughter of Carl C. Richeson.Charlotte had been married previously to an Earl Thomas and they had a daughter.Richard married Charlotte in August, 1920 in Seattle.
Richard left his wife and children in Wisconsin and they eventually divorced.Richard was not on the 1910 or 1920 census with May and their children even though May continued to indicate she was married.The 1930 census shows her as finally divorced.
Richard is so hard to track backwards because his birth dates are quite different on census and military records (1876, 1877, 1870, 1871, etc..).
I think the best lead may be the contact person that he gave for his WW 1 registration.He listed Hannah Longley of Door County.In Wisconsin records, I found a George Whitford who married a Minnie Elmira Longley.George was born in 1869 in Wisconsin and the census records show that his father was born in Ireland and his mother was born in England - same as Richard.
I found a George Whitford (b. abt 1869) in the 1870 census living with John Whitford (b. 1794 in Ireland - although I thik it is a transcription error and should be b. 1824) and Hannah Whitford (b. 1840 in England) and living in Waukesha County.Could George be a brother of Richard?
I will keep searching and try to find strong evidence.