Mike,
Good question. I have added up all the components and total is 162 lb.
That said, my design constraint was to suspend the system from the two surfaces - a 2 x 4 will be on the back wall about a half inch higher than the RPTV. The two boxes will have their rears resting on this. The front of the boxes will be suspended from the 45 deg. sloped ceiling, the load taken by four rafters. The 2440 mid assembly will be suspended from a single rafter at the front with the main load at the rear resting on the 2 x 4 at the wall.
All this was pre-planned in the design. Altough my Mitsubishi dealer claims that he has stood on the top of a 65" RPTV, I don't want that kind of weight on my TV. There will be about 1/2" clearance between the center channel assembly and the RPTV. I will be able to secure the center in place and then roll the TV back to its location.
The picture showing the center assembly resting on the TV is only temporary for a fit check of the concept. No drivers, other than the 075 are currently installed so the total weight now on the TV is slightly less than 100 pounds.
John Y.