Jim & Corey (I helped a little) put the 600lbs on top of the H2 ETMY ISI Keel.  We passed the Keel Mass components (50lbs each) from the floor to the man on a four foot ladder.  In turn the mass was then passed to the man (Jim) standing on the Test Stand.  The mass was placed as per D1000897-v2.  This should put us very close to balanced when the mass is replaced after Cartridge install.