Ok.... I'll take you word for it that it was in 1995. Someone over on the forum says she did have one in 1996 and that it was a public thing and that many people took the tour. (they said a 1000, but in my community it could be in the 100's, maybe 200 or more)
No matter what year it was could Karr have taken the tour? (who knows - if he knew about the Ramsey's before JonBenet's death)
A substitute teacher in a little town in AL would go to Boulder, CO, for a total stranger's open house? I don't think so.