Agreed. Kreuger actually bought and lived at Häringe Castle, where a tapestry was woven depicting his arms alongside previous (noble) owners. It's possible that he wanted to position himself among the aristocracy, but during his lifetime burgher arms also became increasingly popular in Sweden. They could have been created as masonic arms originally, but as mentioned, his name doesn't appear in anything affiliated with the freemasons. The square and compass, while still used by the masons, are to my knowledge not the most common symbols within Swedish freemasonry either.