While seated comfortably in the reading room and thumbing through an old Fine Woodworking (#39) from 1983 this article came to my attention:
Sharpening to a Polished Edge.jpg
This guy was old in 1983. His technique was developed over many years including a few years in a machine shop during WWII.
Charles Riordan explains his preference for the hard felt wheel being due to the softer buffing wheel rounding the edge. With a hard wheel the secondary bevel is more flat and can be touched up on a strop before regrinding.
jtk