Photo #358 from the Colección Witcomb, date unknown. This capture shows the same perspective as another historic photo but much later… judging from the increasingly urban character of Buenos Aires visible towards Calle Azcuénaga in the background.
Update (10 Apr 2013): Something always bothered me about this photo. The single landmark I could find for orientation is facing the wrong way. How can that be? And the height from which the photo was taken means the photographer shot from the bell tower of the Iglesia del Pilar… there’s absolutely no other possibility, past or present.
Remembering that original images were from glass plate negatives, perhaps flipping the image horizontally in Photoshop would fix things. It did; everything fell into place. Below is how the image should look: