I have received so much help from this forum over the years that I wanted to make a small contribution, in case it might be helpful to someone.
I installed Rick's Regulator/Rectifier underneath the rear fuel tank mounting rubber, directly in front of the air cleaner box.
It just so happens that the two holes on either side of the rubber match up with the two mounting ears on the device. I ran 3" screws with fender washers (2 1/2 would fit better) through the holes and through the mounting ears, with a nut on the bottom of each. I held the nut in place with small straight-jawed vice grips, so that I could thread the screw into it. The device now sits there nice and firmly.
I installed the bracket for mounting the air box first.
I tried to attach a photo, but the file size was always too large.