Joe Roark....
Why is it that in "Arnold Schwarzenegger Timeline" [July 1997 & July 2007 Muscle & Fitness issues] when mentioning Arnold's magazine covers, Health & Strength and Muscle Builder are always mentioned, but Albert Busek's Kraft Sport Revue never is? 
You mention Health & Strength as Arnold's first magazine cover, but I would think this is....

You may indeed be correct, and the reason I did not include the mag you mentioned, is because I was unaware of its coverperson history sequence.
Some of Arnold's early contest details are now coming to [a different] sequence thanks to the efforts of David New who bought the then contemporary mags in Germany, had relevant passages translated, and invigorated the traditional storylines and sequences. It is a confusing, tangled trail, and the final reality of what happened may not yet be known. David plans to further investigate.
Perhaps there is another, earlier Arnold cover appearance than the one you show? I simply do not know, but thank you for the correction.