I wish I had a stoplist of the Johnson as built. It may have had a mixture, as Johnsons of that size and era usually did. The Johnson pedal division was likely about as you described. Most older Johnsons had two or three pedal ranks. In the present organ, some of the pedal ranks are "borrowed". For instance, the 16' Lieblich Gedeckt and the 8' flute are the same rank, which is also used in the Swell at 16, 8 and 4 foot. Presently, two flute ranks are on unit chests, the rest is straight. While those two flute ranks are great sounding, another flute rank, the 4' Rhor (Chimney) Flute is one of the nicest stops I have ever heard!
I wish the old Johnson tracker was still there and unaltered, it would be a treasure!