Bobby I did read about Randy Kraft and I agree it's possible that Johnnie may have been one of his victims.
I checked NamUs for Johnnie.
https://www.findthemissing.org/cases/7056/2/
Dental: NA
DNA: Sample available-not yet submitted
Fingerprints: NA
I wish they would submit his sample already, that's a long time for his family to wait.
I still wonder, if Johnnie was a victim of Kraft or another killer, where is his car? JMHO.
I also just checked the Namus page again and in the section marked Police information, it says that he was apparently repoted missing on Septempber 1, 1971. It also gives the name of who I assume to be the detective assigned to the case from the Oxnard Police Dept.