I admittedly know little to nothing about fireplaces/chimneys. We have a wood burning fireplace with a gas starter. It's original with the house, which was built in 1971. We had a cleaning/inspection done and he found a small gap in the flue just at the top of the fireplace. This was not there last year. I'm not sure what could've caused that, but we did have our roof done a couple months ago, if that could've had anything to do with it. What is the fix here? I talked to a chimney restoration guy, and without looking at it he's talking about possibly having to replace everything, including the fireplace. That seems quite extreme, to me. Any ideas?