The right "stone" in my Morso 1410 Squirrel developed a cracked about two months ago. I've still been burning it since I read that cracks in the firebrick are still a go, whereas crumbling is a no-go. Stove performance seems unaffected, but I plan to replace the stone once the burning season is over. The part # according to my parts diagram is 79094700. I've tried to find it online but have had no luck so far. Does anyone know where I can order one? Thanks.