Even though it didn’t generate much interest when I mentioned that I was considering offering sterling silver tubes as an option for high E, Eb and Trad D whistles, I’ve added them to my website anyway.
Maybe a photo of a lovely sliver tube gleaming in the sun will be more effective than just words! 
The price is $170 for a complete whistle, or $75 for just a tube that will fit an existing mouthpiece.
I will not be keeping silver tubing in stock because of the cost, but that shouldn’t cause any noticeable delays in completing orders.
The material supplier I will be using is very prompt in shipping, and does an excellent packing job.