Try to find the spot where the photographer was standing.
The main building in the top left with smaller wing (with four columns) is "Pashkov House" en.wikipedia.org/wiki/Pashkov_House . Photo was made from the western wall of Kremlin, because tree tops in the front of frame (trees of Alexander Garden en.wikipedia.org/wiki/Alexander_Garden ) could be seen from that point only.
Current view with same angle (but lower altitude) is:
Thank you so much for identifying the buildings! You have helped us improve our data on the photograph and I'll add the information to the image in our database as well as on Flickr Commons. Thanks also for posting the Wikipedia links and the recent photo showing us how the Pashkov House looks today.