And here's another one…
1967 Topps Checklist #361
The most obvious difference between the two versions is the dark connection between his left ear and his hat/helmet combo (emphasized via the blue arrow). It appears or disappears depending on which card you have. The other telltale signs are a more rounded/smooth helmet compared to a more jagged look and the appearance of a very noticeable, small, dark spot on top of the black box directly beneath his chin. Also, there is a marked difference between the two versions of the shadowing of his entire chin region. Lastly, the dark shadow on the far edge of his left ear comes and goes.