Vibration Fixed!

OK - Many thanks to those that commented and offered help! We do have a winner, but I am unable to quickly see who it was since the answers came as we converted to the new format.

Quick recap - ( 99 Interstate - 36k on the clock, 20k running Darkside )
I began to feel a buzz in the foot pegs, and tank if I squeezed it with my knees mainly during left turns leaning into it.
Soon the buzz was felt going straight down the road and would only disappear when in a right turn - lean angle!

- CONCLUSION -
BAD LEFT BEARING
I replaced the tire ( running AVON now ) and had the new racing bearings in hand ready to go. The left bearing came out and instantly I knew we had the culprit. Right side was perfect, but changed out the set.
I am showing some minor wear at the bottom of the driveshaft, it was pretty dry as well, top end was fine. Drive splines actually looked great even after 20k without being checked. Lubed it all up with Bel Ray re-installed and I have my baby back!

Thanks again to those that offered comment and help!

Now - who makes the shock mount bushings and the drive dampers?