"The repair was to add a 200mm extension to the upper chimney with another upper chimney section so the flue cover would reach the ceiling. i didnt think that the two upper chimney section wouldnt fit inside each other as they are exactly the same dimensions as opposed to the lower and upper chimney pieces that fit inside each other. it required some trimming with tin snips and then rivets to hold the two upper section in place so i could mount it as one piece. once you get the lower section on it hiolds everything in place but a spare pair of hands is deinfitely recommended. once its all cleaned up in the end it looks pretty good."