I would vote on the journey being made as part of Gothenburg traffic (Lejdtrafiken in Swedish). In 1940 Sweden managed to negotiate a safe passage through Skagerrak with both Germany and Great Britain for Swedish merchant ships. There were requirements by both war going parties like the Swedish ships must be escorted by Swedish war ships to quarantee that neither of the war going parties hijacks those merchant ships and that the ships must strictly trade with nonalgined countries, in essence the US and South American countries.
To make it short: I reckon that would've been the only reasonable way to get out of Sweden to South America in late 1941.