mvzoom, My Weber lid is not perfect either. I found it had smoke billowing out in one spot say 12:00 and at say 6:00, I found a squeeze of the lid fix it. If its your barrel use a aluminum foil as a gasket for the lid. A little air leak shouldn't make to much of a difference on a smoke but will make it hard to shut down. Over time the smoke will seal a lot of the leaks.
UDS with BBQ GURU DigiQ DX2 and a suitcase of beer