I just bought a vermont castings vigilant and come to find out it is a vigilant I. This stove has an oval opening coming out of the stove and I need to find a way to get it to 8" round. The oval measures 5 7/8x 10 3/4, I can't find a pipe to do this in this size. From what I have found out with the vigilant I the size is different. Does anyone know of something I can do? I am anxious to start my stove and get warm. Any ideas would help. Maybe I just need to try and sell this and buy a different stove.