I think that AJ is writing about a Cajun Accordion.
A normal one row Cajun accordion has four reeds for each tone/note you can play for the pull and the push , so there are 80 reeds in a Cajun Accordion in 40 plates. ( I hope these are the right words for it )
Your beautiful oldie have two reeds for every note.( I suppose)

Flat johnny,
Welcome here!
Cool old box. It has pearl-oid buttons like the old Hohners. I have several old boxes like this. The reason it only has one "bar" in the bellows is because it has so few reeds to feed. These old boxes went from 1 stop and evolved into 4 stops in the newer CAJUN built ones, with bigger and longer bellows to feed the additional reed banks.