PS - anything with the square logo over the I (like in post #8) has to be 1995 or later. Probably just a rebranding of some other commonly available mouse at the time that got a logo slapped on it and bundled with systems, since AFAIK AT didn't design any new hardware (besides the Walker, lol). 
Bingo. That was an aftermarket mouse sold in the late 90s by Amiga Technologies/Amiga International. I have a few of them. I don't think it shipped with any Amigas, not even the Magic Pack. There was also a black version.
It is definitely a re-badged mouse from another manufacturer - my university had 3-button USB versions plugged into campus iMacs in 2003.
