Lapham's Quarterly has this graphic up:
Personally I've some doubt over this "win". The language of the Haggadah isn't really clear what Hillel used to do. The Hebrew word KORECH כורך can be either binding, or rolling. Therefore it is easy to understand that
Hillel didn't use two pieces of bread, but rather used something similar to a Lafa (large flat pita). On the other hand, the modern Hebrew word for a sandwich כריך clearly does come from Hillel's Korech.
This is clearly a case for Balashon!