I'm a cheap b*std, so I'd grind a little bevel in the crack, clean it really well with carb cleaner, then jb weld it with 1/4" overlap on either side. Then I'd send the wife on an erand, throw a piece of 220-400 wet sand paper on the glass coffee table, wet it down and slide the adapter over it till I had a clean flat mounting surface. Then when it's all clean and pretty, I'd install a new gasket and hand tighten the nuts with a wrench and call it good. I've never had a weber leak at the gaskets in 10 years of running one so
