I am running into the same problem if you find someone please let me know.
There a few manufacturing companies that still handcraft neckties in the U.S.,but there are a still some. What locations have you looked into. There is a Abbott Neck-wear in Los Angeles and they still work with small custom orders. Obviously, with smaller orders the cost goes up but they have been in business for years. I have worked with them to create small bridal orders making items from self bow ties, ascots, and neckties but I have seen them create custom made vest and shirts so they can create smaller orders. Its a small family business and they work very well with confidentially-from my perspective it extremely important. Hidden Gem in the Garment District in Los Angeles.
Hope that helps