Long time ago in another galaxy........ I am trying to re-arrange my shop and finding things I did not know I had!; I have this contraption, 4 discs made of aluminum, 2-11/16" in diameter numbered from 1 to 4, the two outside discs are #'s 1 and 4 with numbers around the circumference starting at #0 to the left numbers 1 to 37 in odd numbers, to the right numbers 2 to 38 in even numbers and ending with #39, discs #1 and 4 have indentions that mate with discs #2 and 3, 2 and 3 are cut in an angle and by mating these discs the saw blade is at an angle and would cut a groove like some dado heads; I assume that according to the number combinations you could vary the width of the groove, there is not a name of the product only its stamped pat. pend. I believe this came from a Company that was selling kits for making your own table saw.
Hopefully someone remembers this Company just out of curiosity.