The ebony insert. My own notes, just comparing details against serial numbers, suggests that the ebony disappeared some time after 1931. Makes sense. By that time people had determined that the depression was for real and cost-cutting was in order. Having said all that, I do have a note that identified a solitary 1949 gun with the wedge. Everyone cautions you to never say "never."
You see a few other details, like subtly less expansive engraving. Up through '31 the back end of the rib was raised above the breech and, when looking at it from above, was nicely rounded - that went away.
The trail is pretty thin between about 1931 and 1946 because there just aren't that many examples out there.
Those aluminum base pads. I am always amazed that they had a glue 65 years ago that held up so well. I've not seen a single Ithaca pad loose from the aluminum.
