Apparently Ralph's final game was September 15, 2013, Mets v. Miami. I was at that game and took a couple of photos that might be of interest.
First, a zoom-lens look into the Mets' TV booth with Ralph behind the mike..
(Photo taken September 15, 2013. © Gary Dunaier. Link to upload on Flickr.com: here.)
Later, while walking around the ballpark (as I'm wont to do during a game), I was in the team store when I noticed the TV broadcast was showing Ralph with broadcasters Ron Darling and Gary Cohen, so I got a shot of the flat-screen TV...
(Photo taken September 15, 2013. © Gary Dunaier. Link to upload on Flickr.com: here.)