Chaosium kicked off their RPG box set production with a 2″-deep box through 1981. Stormbringer, Call of Cthulhu, and Runequest can all be found in this format in their early editions. In 1982, Chaosium switched to a shallower (lower cost?) 1″-deep box. They would continue with this style through the mid-80’s, before discontinuing boxes altogether in favor of perfect-bound rule books.
So Stormbringer’s 1st editon came in both varieties. (More info on the different printings at our reference site: http://www.waynesbooks.com/ElricStormbringer.html#Prior).
The deep box 1st print is more rare than the later box sets. Call of the Cthulhu’s 1st editon is similar, with a True 1st being considerably more rare than the later shallow boxes. Runequest on the other hand, is reversed, the deep boxes being more common than their smaller descendant.