My friend had a good idea - why not make it out of wood? Makes sense to me! We may have to change the wall thickness in the design, but using poplar or maple or some other fine grained hardwood could work really well. It has the weight, the surface is easy to sand and stain, and it would look gorgeous. On top of that, wood is naturally and organically damped, unlike metal or glass, and will not "ping". It could make for a really effective clamp. So I'm looking into that now - see what it takes to CNC a housing.
jh