My Heat N' Glo Northstar has some deteriorating gaskets around the glass in the doors, and the thicker rope around the doors themselves has gotten squashed flat enough of late that I'm not confident it makes a good seal any more. I can probable "fake it" for the door gasket with supplies from the local hardware store, but the glass gasket has been a real pain to find because it's so skinny, like a 1/4" rope or something. Looking for suggestions, where would you source such a thing?