Tom's Restaurant is at the corner of Broadway and 113th. (They only use the exterior of the restaurant in Seinfeld, the interior is a set and looks nothing like the interior of Tom's.)
Tom's is at the NE corner of 112th St. and Broadway. The food is Greek-owned coffee shop and tastes the same as it did 30 years ago. I can't think of why anyone would go out of their way to go there though it's a regular stop on the "Reality Tour."