We pulled all the 'unplanned' auxiliary payload from the ISI and located the 60kg of makeup mass per D1000906.  This mass is bolted down and with conversation with SUS should not be in the way for Suspension or Template installations.
I was going to survey the table with all the payload removed but I just forgot and then didn't want to unbolt and remove the 60 kg of mass.  It does have substantially less weight on the Optical Table now though and I did shoot the elevations again:

Three of the four shots were exactly the same elevation, the NE corner of the optical Table was 0.1mm higher.