After spending $20 checking the balance on the front wheels and telling me they were fine, the tech tried to send me on my way to have my alignment checked. His boss came out and I asked if a rear balance problem may be causing my issue. He took one look at the right rear and said it was shot:

Holy crap! Yeah, I'd have to agree with his assessment. Here I was mentioning that the vibrations that started around 60 smoothed out a bit around 85. Oh shit oh shit oh shit...