Hi,
You are right in that they dissolved the memberships, but you can go to the stores that used to sell the pieces from the Collector's Society and still find answers. The questions are often known facts or statistics. You just have to hit the right person, one who maybe belonged or worked for Disney the years the Society was active. For example, I was a member and know a lot about the pieces I bought and the pins that came with them. You may find others that will know about your specific pin. They may not be on the forum, because collectors from there did not necessarily collect pins as pin collectors. When I collected the figurines, I used to save the pins, but never even displayed them, because I did not collect pins then. I have many of them still in the boxes the figurines came in. This is just an idea for you. I have found some answers this way myself.