Jim,
From about 1908 through the late 1920's there were several rear sights submitted by inventors to be tested and to be rejected for different reasons. Most of the rear sights mentioned in Brophy's book that were submitted for testing seems to me to be as good - if not better than - the 1905 sight.
Please check Brophys book, pages 452 through 488.
Yes!! this material will be on the next test.
Gary L. Bush
