Hi Andy,
For sure not Alf's. From what I recall, most of his work was spot on, and this emblem is not exact (compared to the "textbook" emblem). See the logo at this link:
http://chrito.users1.50megs.com/_data/divemblems/lwhumans.htm
The brushstrokes, paint flaking and oxidation are consitent with other original painted skins I have found of the era. There are remains of some melted rubber on the back (possibly from a fuel tank)...
here are some better pics:
