This has been enlightening fellas.... Read most of the big thread. Found an open top drum and went to work.
The bottom of my drum fit the weber perfectly but I did not find that out until I had drilled the holes. So....
With the clamp removed my top sealed well. I cut off all of the weber edge except the dome. The weber then dropped right into the inside edge of the barrel top. I cut out the middle of the barrel lid and then slit the remaining edges and bent them up against the inside of the weber. Had it welded together. Sealed it with high temp and that was that.
Thank you for all your help.
You guys are the best.