thanks to you all, yes I did know they were installed improperly. Can't believe they lasted this long but then again a plane or car has not crashed through the house yet and that's what they expect us to contemplate as we do our reports isn't it.
Just like to throw the ball into the court now and then to see what happens.
Got some unexpected comments.
Unusual block also. Somehow can't picture it being used for a flue though.