I posted the questions to an M.E. forum yesterday and it followed a more rigorously mathematical, but similar trajectory to this one. My brother looked over their math and dismissed it as overkill (or just wrong in one case) to demonstrate what he thought was intuitively obvious.

The consensus over there (so far) is there are several vibration-damping materials and designs that should work for the frequency range involved. Choose one and adjust the mounting empirically. If the mat is unsuccessful then go to the fluid-damping. I'm thinking anything more engineering-intensive is simply not worth it, given the flight envelope and data stream we seek.

When we get things going I'll post some pix. Maybe in a week.

B