Though the cover suggests Scarlett is "trapped... on Cobra's Dark Island," there is no mention of Cobra at all in the story. Their name only appears on a financial report (above the name "Red November").
None of the Joe reinforcements are identifiable characters, but at this point, the Joes didn't actually have the greenshirts yet.
Items of note
The first issue not written by Larry Hama since Steven Grant's Clutch-centric fill-in way back in issue 20. That would be 122 consecutive Hama-penned issues.
First appearance: Madame Umbra.
Title returns to "G.I. Joe: Starring Snake-Eyes" (even though he doesn't appear in this issue).
This story was actually written and drawn in 1982, intended as a fill-in issue if needed in the early days of the book. It sat, unused, for more than a decade before being dusted off and given a framing story set in (more) modern times.
Madame Umbra seems to have a bindi dot on her forehead, suggesting she's from South Asia.
Rock 'n Roll mentions Jimi Hendrix's famous rendition of the Star Spangled Banner.
Footnotes and References
↑"M. Hands" was an alias used to denote a group of inkers had worked on the book - the "M" standing for "many." If a book was behind schedule or the art was otherwise late, Marvel would divide the penciled pages among multiple artists to get the work done.