First my stove has a t that runs down thru the top and out the sides of the fire box. I assume this is for heat exchange and some sort of blower. Question is there is a small gap around this pipe going out the side of the fire box what was supposed to be here? Was it brazed or a gasket or did it swell to fit at tem?. Second does any one sell parts for these? Any help or information would be appreciated. Thank you in advance.