Looks pretty good! I think what I did for the other similar cases (where the logo was white, or there wasn't really a clear shot available on the packaging) was take a hi-res scan from the packaging and trace it in Illustrator, as you suggest. From there you can import it into PS and make the drop-shadow (and keep it around in case it ever pops up again in a different color). I can take a crack at it if you can provide a hi-res scan of the box side (it seems to have an un-obscured rendition of the symbol). Otherwise, we can see about using the one you provide here.
Actually, it's been quite a while since I've done any faction work. Are we missing any others?