well, i checked on the archive, and couldn't find it. i'll tell you what i did, tho, so if i missed it, maybe you can check and find it.
see, the archive lets you view stories
by date . it doesn't go all the way back to the beginning, but it does go back to april '96. BGDF aired may 96 (tho there's one NK fic in april). so, i checked each month, april through september and found all the NK fics from that summer.
if i saw one that looked like it might be the one you meant, i opened it and searched the text for the word "jimmy." i didn't find any that contained a jimmy revelation (there was at least one that was about a perry revelation. i remember reading that one when it came out. i don't think clark came back in that one, tho).
there is the story "
jimmy figures it out ," which did come out at that time, but it's very short and makes no mention of NK.
so, anyway, i suggest you go browse by date and see if anything sparks your memory.
Paul