Hi Bill,
One thing that I think would be hugely helpful to you would be to see a physician who understands TMS. Because we aren't physicians, we can't know for sure whether any given diagnosis is TMS. However, a TMS physician knows the anatomy of the thoracic outlet and can give you a real diagnosis. Hearing a diagnosis from an MD, in an office visit, is probably the most helpful steps you can take. Even if there isn't one in your area, no one should have to live with pain, so I think it is fully worth hopping on a plane to visit someone good. Here's our list of TMS doctors:
http://www.tmswiki.org/ppd/Find_a_TMS_Doctor_or_Therapist
TOS was actually my own diagnosis from around '99 to '03. I think I had about 3 or 4 doctors who gave me the diagnosis (though, when I was at a teaching hospital in Augusta, GA, they called it "Droopy Shoulder Syndrome," which is supposed to be a subtype of TOS). That was just one of many many diagnoses I received, including tendonitis, "RSI," myofascial pain syndrome, TOS, tendonosis, tenosynovitis, GERD, irritated vocal folds from improper speech, and Chondromalacia Patella.
You can read my story by clicking on my picture, clicking My Story, aned clicking the links to my video success story (if you're patient, that is). I don't recall whether I mentioned TOS in the video, but it was definitely in the mix! It just never made sense to me, personally, and I had another doctor tell me I didn't have TOS, so it's not one that jumps to top of mind. In my case, I think that some physicians give out a TOS diagnosis because they are fundamentally compassionate, but don't know about TMS, so they don't know what else to do.
Despite my personal experience, I still think it's worth seeing a TMS physician to rule out any genuine structural causes. Obviously, I'm not a doctor, but when you describe numbness that can be rapidly turned on and turned off by an activity (putting your hand over your head), that seems like something that is especially important to check out with a licensed physician who understands TMS. Your health is tremendously valuable, and it is worth taking proper care.