Got into the basement today and was able to get some better pics of the Central Vac as well as the location of the EMS unit.
Here is a front view of the Central Vac
Rather than the cover and having the vac behind the wall, they moved the vac forward a little, cut a circular hole through the single ply, and added a black ring around the edge. The ring around the outside does not look like something that came with the vac, but something that was added to help address thoughts on ways to improve appearance. If you look close, you can see the scoring here that shows the inner hole was cut out (not molded).
Here is where the EMS unit is mounted. It sits between the central vac and the water pump. The remote display is connected using a cord similar to phone line, but I believe the pairs are twisted/crimped differently.