ScottL & Hugh
We added the additional counterweight to the WHAM3's East Side per D1000907.  The table now has 15 stacks, 20kg each for 300kg.  Of course the ISI is locked (as is HEPI) and will remain so until remaining Aux/IO (sorry if I have subsystems smeared) items are added to get to final payload.  Then we'll be able to unlock and fine tune the final actual payload.
I had to adjust the position of the two SUS brackets in the mid-right of the photo to make room for the mass on the Northeast corner.  Further, there was an unused bracket North of PR2 that I moved to the South of PR2--unused in that it was connected to the SEI cabling going from the Optical Table down to the feedthru but connected to nothing on the Optical Table.

See the below photo for a view of the East side.