Well lookie what I found by pure accident why browsing the net, it's none other than a blog post about a set of Japanese 'SegaSonic' clocks which include the Knuckles one that Smindas has as part of his collection. There is also clocks of Sonic, Tails, Amy Rose and Robotnik and they're all rather snazzy. Even the packaging has a hand drawn quality to it. They were apparently found on the Yahoo Japan auction site back in August. Maybe I should have a browse there sometime. I think iI would actually be willing to trade a bunch of my old British Sonic merchindise for some of the wonderful early 90's Japanese stuff.
Source (with more close up photos): Tina @ Animeish