Kris, I believe the tool you are talking about was patented Jan. 30, 1945
patent was applied for on Feb. 9, 1944
Chicago had many stock yards.
so it looks like 6 years later, they protected the patent in Canada.
when looking up this patent, you have to put in; D140193 (D is for design)
patent D140193 was issued to Edward M. Lynn, Chicago, ILL
DESIGN FOR AN EVISCERATING TOOL FOR FOWLS OR THE LIKE.
the picture shows an open loop with serations on a steel & wood handle.
Frank