Problem is it's not a spinning wheel seller, it's a woodworking website with no author listed. It sounds like it's either measurements taken from a relative's old wheel or they they came out of a book.
I'm not sure they've ever actually used the wheel to spin on. They only show it with a single band and don't say the right way to put the double band on.
This should be just like any other double drive.
Petroleum based knitter, removing that nasty oil from the ground one skein at a time.