This tufo block would have made up a wall running E-W, abutting the other ashlar wall 5437. This wall would have been the norther limit of the room, which walls SU 5437, 5438 (possibly 5417) create. Only this block is left of the wall but there are smaller structures on the west side of the ramp to indicate there would have been a wall running E-W. It also clearly creates a corner with 5437.
Long red wall on eastern side of ramp