Here are 2 identical CD 140 jumbo's [No Embossing] with flat tops. What other purpose would there be for such an anomally? I understand that these Jumbos hung upside down in the Boston subways and that the tops were ground down to make room for other structures or subway walls. It sounds logical I guess. Goes to show that not all flat tops are a result of being "Chair Leg Insulators" See the next picture for a close up of tops.

Thanks for looking.

Dan