It appears the source of information I've been using in an attempt to zero-in on the locations where the Ripper's victims were found or attacked, isn't so reliable after all. I stumbled onto another source of information on the Coles location (which was apparently posted since the last time I searched for information on this location), and it showed a different arch than the one which my former reference claims is the site. The new information is consistent with other information I've seen on this location but previously discounted, so I incorporated it into the map. If you keep zooming in on this location, it will eventually switch to Street View mode, and you will see this arch (you might have to rotate the view). I also found a reference which stated that Coles' body was located about 20 feet inside the tunnel, which is why the marker is located on top of the tracks.
So, I'm going to have to double-check all of the locations for which I used this source as a reference, and these are Stride/Henriques, Tabram/Gunthorpe, Kelly/Dorset, Emma Smith/Osborn, and McKenzie/Castle Alley. However, I believe that Coles is the only case in which I relied so heavily on this source, and ignored the other information I had because it seemed too nebulous.