I have a used Barone neck I could sell you. I bought it, used, to put on a cheapo chinese alto just to see what it plays like but the bore was too different. Its in great shape, just a little wear on the cork.
You would have to do a forum search and see if it is compatable bore wise for the yamaha.
I would contact saxquest.com, junkdude.com, usahorn.com, tenormadness.com, pmwoodwind.com, and see it they they have one they could sell you. They have a ton of items that never make it to the website. Ebay must have them from time to time. Are they still being made by yamaha? You could order through a dealer.
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