I have an Ashford 25 wood stove. I can't find the specs on the catalytic converter. The reason I am asking is because I just had it cleaned. The technician indicated he didn't want to remove the catalytic converter because he (nor I) didn't have a spare gasket--and they tend to crumble upon removal. Does anyone have experience with this, ie--what size gasket I would order for the next time I get it cleaned (and want them to inspect converter/go that route up through the stove to clean the pipes above?