The K-Drive kits for our bikes are actually HD Dynaglide brackets, with some extra bolts and 4 small metal sleeves. The sleeves are in two sizes - short for use with a backrest, or long for use without it. A solution with elegant simplicity.
I had to modify the sleeves for use with the trailer hitch, but since I'm probably the only person on this site who has one, noone else need make any changes. They just bolt on and work flawlessly.
