I just got my new National Geographic today in the mail. Inside was a small feature called "ZipUSA, Pittsburgh, Pennsylvania: 15222, Come Hungry". The first page of the article is just a big beautiful picture of a Primanti's sandwich spread over two pages. Luckily, they had the picture online. Behold! The link below:
Also check out the other wonderful pictures (typical of Nat'l Geo) on the left hand side.
Briefly mentioned in the magazine article (though not online) is another Roadfood listed place, Enrico Biscotti.
Certainly sounds like this zip code would be worthy of a pilgrimage!