Michael's copy of the Service Agreement is now available in the Member's area (Technical Information). As he said, it appears to be from late 1929 targeted for the 1930 model year. If that's the case, then 1930 and 1931 should be acceptable years for this item (Not just 1932. Hint hint).
These are very good scanned copies and you can easily blow the image up large enough to see the etchings quite clearly.
Thanks to Michael F (from Australia) for adding to our library.
PS. You can thank him in person at the Tahoe Meet!!