Another reader, Keith Sloan (Welleran), sent me some additional scans of Dungeon Hobby envelope art that he still possesses. As you can see, the art style is identical to that of the previous entry, with the same five adventurers fending off a baddie, in this case a sea serpent of some variety.
Here's the front:
And here's the back:
Keith also sent along a scan of a Dragon magazine mailing envelope, which has some nice artwork on it as well, although it's less impressive than the stuff we've seen for the Dungeon Hobby Shop.
By the time I subscribed to Dragon (starting around issue #65 or thereabouts, maybe a little later), the magazine came in a plain (brown?) mailer without any illustrations or decoration on its outside beyond (I think) the Dragon magazine logo. That's a pity; I really like these quirky envelopes and wish I had seen them back in the day.
Thanks for these, Keith!