I hear you dbb! I know nothing about the Swedish King, or even if Sweden has a King!
Ben Pearson was a huge pioneer of archery in the early 1900's up until his death in the 70's. I cant confirm this, its just a suspicion of mine, but I would almost bet that was a "basement bow" he made because he loved bowyery. I would question whether he mass produced these bows. His fortune was made in fiberglass bows and arrow kits for a less than rich folks. If it where my bow? Id leave it alone and proudly display it until I knew more about it. That could very well be a somewhat personal bow of his.