OK, so I got a Rifle base from Cap'n Bob, and a screen for it from Murph.
But there seems to be a problem. The base doesn't fit nicely onto my fairing. The depression for the vent hits the dashboard plastic, right where the single screw that holds the very front of the dashboard to the fairing is. Removing the screw improves things, but there is still interference.
It looks like I could chop some of the front of the dashboard piece off and make things fit, but I didn't expect to have to do that. Has anyone else run into this issue? Was there a change in the Rifle bases at some point? Is it the later style dashboard that is the problem?