Someone asked this question months ago, and didn't get an answer. To my delight, the Sansom Street Oyster House has Fried Ipswich Belly Clams on the menu as an appetizer. They are luscious, and it is a really large portion. My idea of a lovely lunch is a half dozen Cherrystones or Littlenecks, followed by a plate of these fried beauties.
Waiting for a table can be a problem during the lunch hour, but I usually choose to sit at the bar, without waiting. Almost no one smokes at that bar, and it's fun to see what other folks are ordering.