By playing about with search engine using the words in the Google Books snippet above I have managed to extract the following extract from the relevent page of Sing Out

CO W)2(W ( MM) (>H1^ Cotati, CA Thank you for the song "Hi-Ho-Jcmm" in the fall, 1987, issue of your magazine. You might like to know that it was one of our marching songs when I was with the International Brigades during the war in Spain, 1936-39. ... Sometimes the chorus was rendered: "Hi, Hold ycr rum, ' which makes sense. It's a little late, but I want to thank Pete for attending and contributing to our Veterans' dinner in Hayward a year ago. My son videotaped most of the program; so we can relive the precious moment. I was intrigued by Pete's mention of ...
It sounds like it is a letter to the magazine from an International Brigader living in Cotati California so it will not be Bob Cooney who lived in England and Scotland.
Also, the song was obviously printed in an earlier edition. Can anyone get us closer?