Mystery Photos #131-136: The Duluth Polka Dots?

This contact print of photo negatives comes from Ben Marsen, who many years ago acquired a collection of negatives of scenes from around Duluth. (See Mystery Photo #125 for more info on that.)

Marsen doubts he still has the negatives, so we have to squint a bit and work from the contact strip. Who are these musicians?

Marsen writes that the images were from “a roll of ‘Duluth trip’ photos,” date unknown. “Looking closely, I think their stands in the photo say ‘the Polkadots.’ Maybe you’ve seen the mural on the wall behind the banjo guy? I think Agfa made that film line until ’43.”

Below are best attempts to zoom in on the individual images.