These risers were on my bike when I bought it. As it turns out, I have a much better experience without them! When I pulled them off, the bolts were kind of rusty, so I tossed them and ordered the KB Stepper service kit from Murph's. Turns out, these aren't KB risers. GenMar maybe? I don't know. I don't have any of the original hardware (not that you'd want it) but everything from the KB Service kit will fit perfectly, except the little set screws. You'll have to track those down yourself, I guess.
$40 shipped within the 48