Rather than update the many posts in which I've participated I thought it would be simpler to summarize my experience in a new one.
: vibration and noise, specifically at 30mph.
Severe enough to feel it in my legs and through the foot pegs. Wife gets on the back and the noise would disappear! I could not replicate the problem on the stand. I found about 6 other riders here with the same symptoms, but none were available to share their solution, or perhaps were never solved.
I've been at this for almost a year and have changed every bearing (wheel, steering, swingarm), the universal, fork bushings & seals, rear wheel flange, and tires. I ruled out the speedo housing, fuel tank, headlight bucket, tire inflation, brake rotors, calipers or pads, and heat shields. Basically, I have a new bike.
: a few years ago I had replaced my OEM 1300 SHOWA shocks with used ones from an 1800. The 1800 shocks are just a half inch longer, slightly changing the drive angle. I replaced these with Progressive 412 4234C heavy duty 12" shocks and I am pleased to report that the vibration and noise has completely disappeared.