Might be interesting to see what VS could come up with in volume.
In the meantime, Bruce, most, if not all, local auto upholstery guys can get Stayfast material - there are about a dozen different colors to choose from, and there are two levels, expensive and really expensive.
The stuff from CMC is standard convertible top material, similar to what came on most American cars, and it costs between $50 and $75 per yard. I know, 'cause I just bought a yard locally to install "pockets" for my high-backed 914 seats in my tonneau. Stretches a bit when hot, not too flexible when cold (but you know all that).
Next step up is to StayFast - more cloth-like, much nicer feeling and much more flexible when colder while not stretching all that much when hot. It costs around $100 - $150 per yard and some of it has a nice inner lining.
Then there's the really expensive stuff, even softer and more flexible, lined with a nice interior material, usually available from the high end classic car interior installers and suppliers, and goes for $300+ per yard.
ALL of this stuff can be found in Hemmings Motor News, along with reputible suppliers who will sell you material by the yard (lots of colors, too) which your wife can stitch up. She'll need canvass needles for her machine, but it's pretty easy stuff to work with.
Hope this helps, but I still would like to see if Kirk could do something for us, or we could find his supplier. It's got to be easier and cheaper to turn out ten or more of these than to do just one.