For the record (and long overdue), here is the payload weight of the SUS components on BSC8:

44 lbs = 8 x 5.5 lbs for Vibration Absorbers
~60 lbs  = FMy Stays
~2 lbs = FMy Sheer Plate dampers
10 lbs  = Cabling   
2 lbs = Cable Brackets
3 lbs  = Ring Heater + Brackets + Cables
266 lbs = ITMy QUAD Upper Structure
531 lbs = ITMy QUAD Lower Structure
44 lbs = QUAD Sleeve
2 lbs = QUAD sleeve wedges
341 lbs = FMy SUS (weighed in at 394lbs with the 53 lb LSAT attached prior to install)
55 lbs = 1.26 lbs X Dog Clamps (33 long + 22 short)

TOTAL = 1360 lbs = 641 kg