Interesting. The only bronze cent of that era I have found is dated 1998. It says that its size is 19.10 mm, but nothing is said about the weight. And that's the only date listed. Of course this one has a different km, which is km#289a. But since you seem to have one, and the WC is full of mistakes, if the file is not already created, you can do it yourself, I'll just have to check it after. If you could post pictures of yours that would be appreciated. Have you tried to do a search on Google about that ?
Si tu cognes ta tête contre une cruche et que ça sonne creux, ce n'est pas forcément la cruche... lollll mon proverbe préféré !