ISO posters from '96 and '98

Okay, so finally taking inventory of shows I've attended and posters I have to go with those shows...out of 28 shows...I am missing 3 posters...I'm sure this is a fairytale request...but I am looking for '96 Merriweather (Columbia, MD), '98 Merriweather, and '98 Atlanta. Any suggestions about where to look? Or better yet...does anyone have one of these they would be willing to part with (for a price, course)