Email from Gerald Jacobson on November 30, 2023.

 "Did a little more research—there are a couple of sites now that were not there a few years ago and unlike the Herald lets you see the archives without subscription. Robert apparently used his middle name almost exclusively. Calvin was his real first name if the headstone is to be believed. He died February 7, 1979 at Utah Valley Hospital of cancer (surprising since he had a congenital heart condition that never hampered him much growing up). The obituary is on page 4 of the Herald February 8, 1979. The funeral service was in the Orem Berg mortuary on February 9. He is buried in Orem Cemetery. A picture of the gravestone can be found online—it  comes up if you google the full name. By the way—our class had only one Robert Christensen.

Jake"

Note from Bob Valentine:  I had Robert listed as "lost" until today.  Thankyou Jake for finding him.