The St. Paul city directories for 1882-1885 note that Carl N. Ekman, together with his brother Henry (Olaf Henrik) owned and operated a dry goods and notions business in St. Paul, called Ekman Brothers & Carlson. So who was Carlson? Checking all the Carlsons in the relevant directories show that he was John P. Carlson, who lived at 689 DeSoto in St. Paul, and also that someone else, presumably a brother of John P., Gustav N. Carlson listed as boarding at the same address as John P., acted as clerk.

 My next move will be to see whether I can find out anything about John and Gustav Carlson (for instance, did Carl Ekman know them from Växjö?) and see whether the shop ever advertised in the local papers.