I was able to get the cradle riveted tonight. although I realized that since the correct length rivets, I have in stock were countersunk, I needed to c/s some more holes in the cradle frame, which was unplanned, but ok. So, I countersunk some more holes and then riveted up the frame and floor. It really is a strong piece. With the nutplates installed to secure the backup battery, I installed the battery and then did an install of the cradle in the fuse.
I plan to paint this the same color as the interior, but that will be later...if the contrast doesn't grow on me.