Paul yes it can be done in HO also, in fact it is a bit easier in HO as there are a few more detail castings to use then in O. In this piece in fact several of the commercial details are HO castings that look "right" for O also. As for what it would look like in HO, that would also depend on the viewing distance, I did several small stores for a layout with quite similar interior details a couple of years ago that were being set in about 20-24" from the edge and they came off quite nice. It is also possible in HO to do the quite a lot of the interior using color photos with only the few pieces in the middle of the room being actual 3D depending on the distance this can give a terrific effect and look "real".