Huh, I'll kepp the soft mout idea in mind. Before I read that I made the carb manifold and split ring. The intake maniforld is bolted to the split ring. The split ring is afew thousands lower than the flat face of the boss on the jug. That permits a good seal. I guess the good news is that by using the split ring I did not mess up the jug. I could go ahead and use the rubber boot if it looks like and advantage.

Here is a tip for making two holes meet in the middle, like for the pulse pressure tap the carb uses. Look at the thing real carefully and make use the planned route does not come out the side. Start each side of the hole in the normal way. Put a slightly smaller bit in the drill press vice and secure it such that the bit in the chuck line up with it. Drill the hole a little alternatly from both sides using the bit shank in the drill table vice to align the work. They will meet up in the middle.