A quick search doesn't bring up anything else re violins in conjunction with Thurston Holmdale or Torsten Holmdahl. He is always listed as an "artist" or "scenic artist", never as a "violin maker". Unless others have knowledge of other instruments by him, I would be very skeptical that he was the maker of this violin. In 1918 he was still signing documents, etc. using the original spelling of his name (Torsten Holmdahl), and it seems that if he was the maker he would have used that spelling rather than the "Americanized" version. I also noted his documented handwriting and written numbers at the time were very neatly executed, as might be expected of an artist, and in contrast to the rather crudely made inscription inside the violin, although it is certainly possible someone else added the inscription later. At any rate, someone with the ability to produce an instrument like this, would surely have made others.