Hello everyone. Hoping for some help here. We purchased a 100 year old home with a gorgeous hand built fireplace. I was in the process of cleaning it out and noticed the damper does not want to fully close. It seems it is backed up with some build up which I will vacuum out. Anyway, the damper has vertical slots which means when it is closed air still comes through....that seems so strange to me and with. I yet coming not sure what to do. Has anyone come across a damper with holes in it? Thanks in advance.