The info above came from a tabulation Ithaca sent out to folks inquiring about such things back in the 1960s. Walts's work with the records likely shows slightly adjusted numbers. I've always wondered about that tabulation as it lists three 5E 28-gauge NIDs and I'd seen and handled three different Grade 5E 28-gauge NIDs by the early 1990s, and have heard of another; when I've seen far fewer examples of guns that were supposed to have been produced in greater numbers.