Was at the site 2/19/2013. Here is the up-to-date signage at the Brush Stairway in Upper Manhattan, site of the Polo Grounds.
Here was where the stairway was. It has been completely removed with visible restoration very much underway. The landing with the inscription has also been removed and is being resurfaced etc. to look like it used to in 1913 when the stairs were built. Should be beautiful when completed and a big assest to the community as the walk down and around the bluff must be difficult and time consuming.