Im about to send a gasket out to a guy that makes flanges. He sells them for pretty cheap as well. If your looking for one, let me know and I will have him make more. He is in canada, so I would have him ship them all to me, then I could distribute them. Not looking to make any money on this, just trying to help some people out.
they will be 3/8" thick, and should cost about 40 dollars to your door. He can make them in stainless as well if your interested I can inquire on cost.