Interviews with the artifact's namesake
Tim Kask gives some clues, though he never actually says what Kwalish was. Most of this is taken from his years-long Q&A on the Dragonfoot forums:
- Kask was a first employee and early and prominent editor for O(School)D&D back in the 1970s-1980s (he was responsible for magic missiles never missing among other things).
- He was once responsible for getting out Dragon Magazine and wrote an article under the pseudonym Omar Kwalish (Dragon Issue #7, about when you forget your dice, a popular article he said was created under a bong haze the night before the magazine needed a full page of something). (2008 answer).
- In 1974, Kask ran a campaign for his friends in which the bad guy was called "Kwalish." (2013 answer).
- Kask added that many of the artifacts were named after themselves or things from their campaigns (a precursor to "easter eggs" in video games). When someone needed a name for their crawdad contraption, Kwalish came up. (The Sword of Kas
k was also named for him).
- Kwalish started out as Kask's PC when he was in high school. However, he rarely got to play, so Kwalish became a go-to NPC that other players could hire or for magical services. (2008 answer).
- Kwalish owned several cool magical apparatuses and items.
- Kask didn't DM a ton, but he planned on doing a convention adventure The Hall of Wonders, a place where the powerful mage Kwalish stored his cache of cool items.
- In a 2007 answer, Kask said Kwalish was his 1st PC. He then turned him into a mythical NPC during college for his gamers, in the Kwalishar Ruins. He says (in small print) that user "grodog" may have campaign notes.
- As referenced by @Alzrius, the link provides some more lore and Kwalish references. One of our own mods in 2016 visualized Kwalish as a gnome despite the game rules that, at the time, didn't allow for it to fit a high-level enchanter.
Here's where I argue that Kwalish wasn't a gnome, absent Mr. Kask saying otherwise. In OD&D, gnomes could NOT be the class Magic-User. Instead, there was a separate class called the
Illusionist that they could advance in (usually multi-classed because demihumans often capped out before level 20). You wouldn't use the two interchangeably. If you were playing a magic user, you wouldn't be playing a gnome. If you wanted to advance to level 20 as a caster (and with the description of Kwalish as an ultra powerful caster), you'd have to play a Human. Further, the item was originally described in the DMG (p137) as being fitted for "two human-sized persons" (not gnome-sized). Also, in OD&D, gnomes weren't inventors and craftsmen. That didn't come till later, so Kwalish as a gnome is more a modern take than an original take.
That all said, it probably really doesn't matter except to perhaps Mr. Kask, but to answer the original question, I don't see it ever being covered specifically in any prior edition.