Duane, is it possible you mean the picture posted by Ray in post #422 at page 17? Says modified Astro, was published April 1960, though.

Somewhere else was mentioned (also by Ray?) that MAN Feb 1957 specifies Smog Hog and MAN April 1958 specifies Astro Hog. Unfortunately, I don't know where it was posted (search might help), but at least the sources are known.