In 1911, the Ithaca Gun Company introduced their first single-barrel shotgun especially designed for trapshooting. This was known around the Ithaca Plant as the Flues Model after it's designer Emil Flues.
In 1922 the Flues model was discontinued when the current model was introduced.
All guns of the earlier Flues model have serial numbers under 400,000.
The 1922 version was designed by Frank Knickerbocker and is called the Knick model.
*“The Ithaca Gun Company From the Beginning” by Walter Claude Snyder