Hello, I have what appears to be an earth stove, can anyone help me identify the model or tell me more about it? I'm not sure if it's a proper insert or a zero clearance. We are going to pull it to replace, but are trying to figure out if we need to budget for rebuilding the fireplace as well as the new stove, liner, and installation. 1970's home. Chimney has no liner. Also, it's our only heat source for our main half of the house so trying to figure this out BEFORE pulling it if possible since we will push it out til it warms up more if we will need to spend more time on the project. Thanks for your help!