Hi DavidHC
Thanks for sharing your journey and the info you've researched.
I have PN (probably autoimmune SFN) but the neurologist says there's too many things going on health-wise to establish a definite diagnosis/cause. (Primary Addison's Disease (adrenal failure), Osteoarthritis, Sicca syndrome, TN + other stuff). Like you I've found lots of useful info here on NT.
If you haven't read the PN stickies here are links to a couple with lots of info and directions to other links & websites:
http://neurotalk.psychcentral.com/thread177.html (started by Liza Jane)
http://neurotalk.psychcentral.com/thread43699.html (started by Liza Jane)
If you go to page 2 of the second thread there is 3-part post(s) by a member named Wing42 that has information on diet & supplements to reduce PN.
All the best for your continued treatment. You've done exceptionally well to turn your lifestyle around - hope it brings you more improvements.