Will,
I'm completely out of my element here, but you are sort of well-known at least by name in the industry, so what if you called some of the boutique manufacturers and enlisted their help and advice in finding a solution? I'm thinking of Nelson Pass, because he's very friendly or maybe the guys at Coda.
There are probably many others that have ideas about a supplier who could make these to your spec. because they've had to shop for the same thing at some point.