Was his father Chalmer V or Chalmer S. ? See mother's notes, she married them both. Guessing it was Chalmer S. because of his birth year.
KEEBAUGH, Robert G. * FAIRVIEW b-15 Dec. 1926; d-12 Nov. 1983; w-Josephine Hershey; p-Chalmer & Mary Mock Keebaugh; WWII
FCHS Cemetery Disk, 1997
"...deceased husband, Robert G. KEEBAUGH, died Nov. 12, 1983. They were married April 12, 1945..."
Source: Obituary of wife, Josephine L. (Price) KEEBAUGH, Herald Mail [online] 3/21/2k.