Wow, that's fascinating Dave! I'd never heard of Sorbothane! OK, I see what you are saying.
I think what you suggest would get everything but the walls of the dome themselves. The dome weighs about 650 lbs, and the motors for it vibrate a good deal. Would it be possible to make shims of this stuff and put them between the sections of the walls where they are bolted together? (Otherwise I'd have to remove the shutter and dome, and install pucks of the stuff between a pair of the rings. Removing the dome is the labor intensive part of the process.
What about pads of sorbothane under the pier itself? The pier is mounted via j-bolts to a plate imbedded in the concrete. I can pretty easily remove it, and add material under it.