The vibrations emanate from the engine (doh). It's a big single. Most of the vibes are transmitted up the front frame tube.
Places to wave the torque wrench and Loctite at the special RE self-loosening nuts, I've done all these and lessened the vibrations -
The head stay.
The front engine mount; loosen the big bolt, run the motor to reseat the engine and tighten the bolt up.
All engine mounts.
Swinging arm bolt (torque wrench!).
Frame bolts, items 7 & 8 & 13 here
http://www.hitchcocksmotorcycles.com/pa ... 3481/Frame
Doing the last two seemed to take quite a bit of vibration away. The swinging arm only needed about 1/4 turn but the frame bolts took quite a bit more.
Running the engine at high revs, to 5000+rpm up through the gears, does seem to lessen the vibrations. Vibrations seem to get less from 1500 to 2000 miles on the clock anyway. I would not do the first 300 miles like that but it doesn't do to baby it too much. You should be able to feel when the engine has loosened up enough to use more revs. It would also seem that the more you use high revs, the more the engine likes using high revs and gets less buzzy.
The handlebar mounts can be overtightened and stretch the plate, I've had to replace the U-shaped plate as it ceased to grip the bars, elongated holes; use the torque wrench. I got less bar tingle after replacing the plate.
The long bar-end weights bolts are just long M8 Allens, a longer bolt may add some more weight. I have a standard weight on the left but a Halcyon mirror on the right, it seems to work well enough. I have no urge to fit a bar-snake or fill the bars with lead shot.