Well all decisions ARE made in the brain, conscious or not, and whatever consciousness is, it resides in those neurons. That is also influenced by various inputs of the rest of the body, of course, but I think we can safely assume "self" exists in the brain. Thinking it reversely, can we really say an organism with various complex parts but no brain has consciousness?

You are not a disconnected consciousness, but some body parts are more easily discarded than others, and I think the brain tops most (all?) of the others regarding survivability - and is irreplaceable regarding the "self".

How can we be certain that the consciousness is in the head-brain? For example, there are 100M neuro cells in the stomach. We also talk about making decisions based on "gut feeling". I am not saying it is any kind of proof, but hints that this saying might be based on physical experience about gut being involved in the decision making. Also, meditation traditions talk about various body parts having various kind of impact on the consciousness, stomach being one of them.

Another interesting example is the octopus. If you cut a tentacle off from the octopus, the tentacle sometimes still continues to feed the head of the octopus. So the tentacle appears to have a "brain".