FWIW, this is a ten or so (? got it from a friend) year old Rolf Vector Comp wheel/hub and from what I could find on the 'net it was made by DT Swiss but Rolf apparently has no interest in customer support for these older wheels.
I have too many bikes, am too frugal, and value too much the ability to mix & match parts (even if this particular mix/match doesn't work out) on my bikes to imagine paying real money for a conversion cassette. Shiftmate still beats that option in my mind for the cost + the fact that the one I need could actually prove useful for other setups I may decide to run in the future on other bikes.
Thanks all for the feedback & info.