Since the likelihood of my current existence is unimaginably small if the specific brain produces the specific self...
Asked and answered. You have not shown that this statistical factoid is the governing principle in the formation of the "self," or in fact of anything. You have struggled in vain to show a difference between your "self" and the defeating counterexample, but you cannot do so without begging the question and reasoning in a circle.
And if you are talking about "likelihoods" again, are you trying to return to a mathematical level of rigor in your proof? Or are you just couching your wild guesses in math-sounding language?
...all I need to show is that there is a reasonable possibility that the brain is a receiver, rather than a producer, of consciousness.
Nonsense. You're affirmatively formulating an entirely new model for consciousness. Your hypothesis proposes a completely new mechanism for how it operates in the qualitative sense, and requires an entirely new and hitherto unknown phenomenon as a vital component. This hypothesis is being proposed in direct contravention of a reasonably functional theory to the contrary.
The notion that you need no evidence for this is preposterous.
If you agree, I'll see how much evidence I can find that the brain could be a receiver rather than a producer.
I do not agree
at all with your formulation of the problem, and not just in that absolves you of all meaningful burden of proof. It is your hypothesis that the brain "receives" consciousness. You have the burden to prove it. That burden is not even remotely approached, much less carried, by suggesting merely that it is not impossible.
You are simply trying to foist as axioms the key tenets of your claim. Since you were unsuccessful at getting the classical model of consciousness to fit your beliefs, you're trying to create out of thin air a new concept that embodies everything you need for immortality and a new hypothetical method of its operation. As others have noted, this is equivalent to setting aside the universal laws of nature as the governing forces and postulating some new unknown force that is the "real" reason things are the way we observe them to be.
This is no different than you trying to foist your personal definition of "evidence" in the shroud thread as a condition of allowing the discussion to proceed. You may not force your critics to accept your personal definitions and a condition for having the debate.