Let me hear some opinions/experiences with these tops. You gus are the experts.
I hate to be the one to tell you but nothing will turn out completely perfect there will be little flaws here and there as far as a good seal on the lid there are a few options i can think of... 1st you could take that high temp rtv gasket and put a bead around the lid and place a layer of plastic suran wrap on the drum where the rtv would form to the drum without it sticking to the drum as well to the lid. but so that it will form to the shape of the drum. and let that sit overnight. 2nd you could use that nomex gasket but i would think you would have issues with that lid not weighing enough to get a good seal but to fix that you could attach some clamps that would hold the lid down.. the same with those rope woodstove gaskets...
Have you tested it as is? How tight is the fit without the o-ring? I would build it and do some test runs before sinking $50 into nomex. On my UDS I used a weber lid and hammered the lid to the drum. It is sort of a pain since it has to go back on the same way every time but it works and it was a free fix.
The smoker is almost ready to go with the exception of the charcoal basket. That will happen this weekend. The top is slightly warped and there is no gasket that will seal that. I ordered these and I think this should fix the problem with the top.
How did it turn out? Do you have pics?
Don't get anal about how "sealed up the lid is. Where you see "leak"- I see "a tad more exhaust"
TBH it is really just gonna matter when you shut the drum down and try to snuff /save the coals.
If it's not too warped, you can set a pc of plywood and a weight on top to make it flatter when you go to shut it down.
or you can put your latches on- those should work just dandy.
I guess I did KINDA leave y'all hanging so I took some pics yesterday to show how it came out. I fashioned the charcoal basket after Sneeaky1's basket but the expanded metal I used was a beast. I bough a 4x8 sheet of the good stuff so I could also make a grill grate for a pit I have. It was rough getting it bent and once I had it close I tack welded it. As for the clamps, they worked perfectly!! The lid was too warped to even make an acceptable seal and the coal would have to run out not be put out after a cook. There is still a tiny bit of smoke coming out in 1 spot but it doesn't bother me. I run with the exhaust wide open so .... no worries. I love the exhaust flap. It's cheap and functions perfectly. I can rotate it to closed and put the magnets over the holes and the fire is out. This spring I am going to build another one, position the grill grates a little differently.