Very nice capture, that was exactly what I meant in this post. See how the cutouts allow certain bolts to remain even if the cylinder is unbolted?
On the round flange end you will see 6 (i believe) notches or cutouts around the flange. I have seen those in the past where the flange end will sit on a surface with existing (6 or 3) bolts protruding. The bolt heads or nuts will line up with those cutouts, extend thru the opening, and that will allow the flange to sit flat on the surface. It is then bolted down using the round holes you see.
they continued to move the UYOs one by one and i just noticed a forklift moving the recently built crates. i have a feeling the next time we see the entire assembly bay the UYOs may have been shipped out.