Here is another Watchtower quote that shows that Malcom Rutherford was an active Watchtower supporter. This excerpt is from J.F. Rutherford's letter to Russell re the Troy Debate, which was published in the May 1, 1915 WT. This proves that Malcom Rutherford was working alongside his Dad at least some of the time. Probably more. Malcom simply was not getting mentioned in the publications for his work with both CTR and JFR.
"I shall never be able to thank you as I would like for the letter which was signed by yourself and all the Bethel family, assuring me of your united and continued prayers in my behalf. The Lord reward all of you. This is but a reminder of the unity of the body and the sweet relationship we are privileged to enjoy here. How much sweeter it will be in the Kingdom! Brother Woodworth suggested that there must be great interest in Heaven in this debate. The Lord be praised for it all. I am thankful indeed that He was pleased to use me to glorify His dear name in any manner. Brothers Woodworth and MacMillan sat with me on the platform as counsel, and my son was by my side to take anything quickly that I desired and to prepare the copy for me without delay. All rendered valuable service. The Lord arranged it all.