Guess I should have read your first message "decorative closed off fireplace". I think you need to know more about that like why it was closed off. I guessed coal from the small size -- obviously it's too small to burn wood, but 1942 was well past the coal era. Curious what makes you think, you can now burn wood in it. Would think the first order would be a professional inspection by someone certified to determine feasibility of using the flue/chimney for wood burning.