Hi there abrogard and welcome to the forum. Wow, normally a breaker bar would get that nut off fairly easily if held in a vice, try again and if it fails you'll have to go down to your local mechanic and ask him to zap it off for you with the rattle gun if you don't have one. As for the blob on the bottom (known as a "boss"), yes, it's a tapered seat so rest it on an anvil or a nice solid object like the top of a sturdy vice and give it a clean sharp blow on the side with a hammer. This should break the seal and it should just drop off. Good luck and let us know how you go.
