I forgot I had this screenshot, and looking at it, I realized it would be a neat Wiki mining effort to try to ID the caricatures. But outside of Tony Randall (fairly obvious on the far bottom right), I really can't figure anyone else out (a few look familiar, but I can't be sure). This is probably mostly for someone like Nate next time he checks in, but if anybody can help, please do.
For referencing help, here's Wikipedia's list of people whose caricatures hang in Sardi's, but without more time to do a one by one elimination, I haven't found it that helpful.
It was the real Sardi's, the real caricature wall, and the real owner even, although no doubt they had to do some rejiggering for the Mupps (and of course, presumably they weren't serving lunch at that time).
It seems the now out of print book Off the Wall at Sardi's (1991), in addition to including 200 plus of the caricatures, discusses other aspects *including* Muppets Take Manhattan in passing. Copies run for forty bucks or more, but that's what interlibrary loan is for!
Okay, a few more here and there: I spotted Gregory Hines in pic 19! (I wonder how many folks in the movie also had their caricatures in that scene). In Pic 4, on the lower left, it's Betty Comden and Adolph Green (and since they wrote songs used on Muppet Show, they now get a page). Lena Horne is below Angela Lansbury (notably in pic 13). Walter Matthau is in several of the wide crowd shots, recognizable by puffy cheeks (now just have to decide which pic to use). So little by little.
Heh, first message: "But outside of Tony Randall (fairly obvious on the far bottom right)..." Just so it's clear that I know my Randalls. (He's the only one I spotted without further help or research, though; there's one in there of Jerry Stiller which once you know, okay, you can see the resemblance, but otherwise...)
Thanks, Nate! I hoped this wouldn't be too taxing for you (ahem).
I'm the co-author of "Off The Wall at Sardi's" and when I was working on the book with the late Vincent Sardi, he recalled the Muppet shoot as one of the most enjoyable and had great fun playing himself. The book is back in print and on sale at Sardi's Restaurant and their website (www.sardis.com) if you want a copy.