Griff,
Our posts crossed. There is no conversion between 10Hz cu and 100Hz. 100Hz cu is a measure of tracking ability at 100Hz, not compliance. We've converted some AT dynamic cu by measuring resonant frequency on known arms, and have a sliding conversion scale, but it doesn't always hold true, especially at the extremes.
VTF might give a better idea and better yet a test record accurate even for an individual sample of a cart model.
Regards,