Dawnette posted a comment to the effect that Paul Hollopeter had also changed his surname to Holly. Based on this information I searched ancestry for Paul Holly and was able to find an SSDI entry and a California Death Index entry. Following is the information I have collected so far on Paul:
Name: Paul HOLLOPETER
Sex: Male
Father: Harlow Bryant HOLLOPETER (1859-1951)
Mother: Ella B. VARNER (1864-1957)
Birth 6 May 1899 Creighton, Cass, Missouri, United States
Census 22 Apr 1910 Bear Creek Township, Henry, Missouri, United States
Occupation 1919 Agent for the Missouri, Kansas and Texas Railroad Company; Henry, Missouri, United States
Death 4 Jan 1991 (age 91) Palm Springs, Riverside, California, United States
Alt. Name Paul HOLLY
Marriages/Children
1. Bernice WHITE (1900-1985)
Marriage 2 Aug 1919 Clinton, Henry, Missouri, United States
Children Gene HOLLOPETER (1925- )
Obviously I have much more research to do on Paul (census and military records) but I now have a good foundation to work from.