Any chance those codes are telephone numbers?

Old people know that seven-digit phone numbers used to start with an "exchange," which was simply a word. Your phone number might be Overland 5-4321, and you'd tell everyone your phone number was "OV 5-4321."

Later on the exchanges were dropped and only numbers were used. The above phone number became "685-4321."

The codes above, like TD Aquarium 27200, could be TD 2-7200. Or 835-7200. Extra numbers could indicate extensions. Supposedly they'd know the area code by the name of the town.

Just a thought.