The waitress brings two pots of coffee to George and Seinfeld, some banter occurs, she walks away without pouring George any coffee, and then George has a full cup of coffee.
Jerry's address is mentioned as 129 W. 81st Street a few times. However, the awning in front of his building has the address 757.
When Kessler is walking over to the sofa with the sandwich in his hand, there is a reaction of shot of Jerry, sitting on the sofa looking at him and leaning forward to the coffee table, lifting the cereal spoon to his mouth. Kessler points at the newspapers to get Jerry to move them and in the next shot, Jerry is leaning back in the sofa, hands on this thighs, no spoon in his hand.
When Kessler is eating the sandwich, large chunks of meat dangle from his mouth. In the next shot, his mouth is empty and he takes another large bite.
Jerry and George go to meet Laura's flight at Kennedy airport (JFK). Kennedy handles long distance flights - transcontinental (beyond Denver) or international. At the time of this episode, someone going to New York from Lansing, MI (on United, as shown) would connect in Cleveland or Chicago O'Hare and land at LaGuardia or possibly Newark (code EWR - like the yellow piece of paper stuck to Jerry's fridge).
When Jerry sits on his couch right before he receives a wrong number call and Kessler walks in, he is seen wearing a blue long sleeve shirt with a white undershirt. When he takes out the shirt before sitting down you can see he is clearly wearing a mic taped to his torso.